Sample records for haloacetic acids haa5

  1. HALOACETIC ACIDS PERTURB PROTEIN PHOSPHORYLATION IN MOUSE EMBRYOS IN VITRO

    EPA Science Inventory

    HALOACETIC ACIDS PERTURB PROTEIN PHOSPHORYLATION IN MOUSE EMBRYOS IN VITRO. MR Blanton and ES Hunter. Reproductive Toxicology Division, NHEERL, ORD, US EPA, RTP, NC, USA. Sponsor: JM Rogers. Haloacetic Acids (HAAs) formed during the disinfection process are present in drin...

  2. Reducing and verifying haloacetic acids in treated drinking water using a biological filter system.

    PubMed

    Lou, Jie C; Chan, Hung Y; Yang, Chih Y; Tseng, Wei B; Han, Jia Y

    2014-01-01

    This study focused on reducing the haloacetic acid (HAA) concentrations in treated drinking water. HAA has been thought to be one possible nutrient supporting heterotrophic bacteria regrowth in drinking water. In this study, experiments were conducted using a pilot-scale system to evaluate the efficiency of biological filters (BF) for reducing excess HAA concentrations in water. The BF system reduced the total HAA concentration and the concentrations of five HAA species in the water. Dichloroacetic acid (DCAA), monobromoacetic acid (MBAA) and dibromoacetic acid (DBAA) were the three main HAA5 species that were present in the treated drinking water in this investigation. Combined, these three species represent approximately 77% of the HAA5 in the finished water after BF. The verification of the empirical HAA equation for the outlet in the BF system indicated linear relationships with high correlation coefficients. The empirical equation for the HAA5 concentrations in the finished water was established by examining other nutrients (e.g., dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm wavelength (UV254), and ammonia nitrogen) that can reduce pathogenic contamination. These findings may be useful for designing advanced processes for conventional water treatment plants or for managing water treatment and distribution systems for providing high-quality drinking water. PMID:25320856

  3. GENOMIC ANALYSIS OF THE TESTICULAR TOXICITY OF HALOACETIC ACIDS

    EPA Science Inventory

    Genomic analysis of the testicular toxicity of haloacetic acids David J. Dix and John C. Rockett Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, R...

  4. METABOLISM, MICROFLORA EFFECTS, AND GENOTOXICITY IN HALOACETIC ACID-TREATED CULTURES OF RAT CECAL MICROBIOTA

    EPA Science Inventory

    Haloacetic acids are by-products of drinking water disinfection. Several compounds in this class are genotoxic and have been identified as rodent hepatocarcinogens. Enzymes produced by the normal intestinal bacteria can transform some promutagens and procarcinogens to their bio...

  5. Environmentally Realistic Mixtures of Haloacetic Acids Exhibit Concentration-Dependent Departures from Dose Additivity

    EPA Science Inventory

    Disinfection byproducts (DBPs), including haloacetic acids (HAAs), are formed when oxidizing disinfectants react with inorganic and organic matter in water. Drinking water is assayed routinely for 9 HAAs (HAA9): chloro-, dichloro-, trichloro-, bromo-, dibromo-, tribrorno-, bromoc...

  6. Nine and Ten chemical haloacetic acid mixtures exhibit concentration-dependent departure from dose additivity

    EPA Science Inventory

    Disinfection of water greatly decreases waterborne disease. Disinfection byproducts (DBPs), including haloacetic acids (HAAs), are formed when oxidizing disinfectants react with inorganic and organic matter in water. Water providers routinely assay for 9 HAAs in finished drinking...

  7. Mammalian Cell Cytotoxicity and Genotoxicity of the Haloacetic Acids, A Major Class of Drinking Water Disinfection By-Products

    EPA Science Inventory

    The haloacetic acids (HAAs) are disinfection by-products (DBPs) that are formed during the disinfection of drinking water, wastewaters and recreational pool waters. Currently, five HAAs [bromoacetic acid (BAA), dibromoacetic acid (DBAA), chloroacetic acid (CAA), dichloroacetic ac...

  8. MICROEXTRACTION OF NINE HALOACETIC ACIDS IN DRINKING WATER AT MICROGRAM PER LITER LEVELS WITH ELECTROSPRAY-MASS SPECTROMETRY OF STABLE ASSOCIATION COMPLEXES

    EPA Science Inventory

    Haloacetic acids are disinfection by-products of the chlorination of drinking water. This paper presents the analysis of all nine chloro- and bromo-haloacetic acids (HAA9) at sub- ug L-1 by microextraction with detection by electrospray mass spectrometry. The haloacetic acids are...

  9. BROMOCHLORO-HALOACETIC ACIDS: EFFECTS ON MOUSE EMBRYOS IN VITRO AND QSAR CONSIDERATIONS

    EPA Science Inventory

    The haloacetic acids (HAA) are a family of chemicals that are drinking water disinfection byproducts. We previously reported that bromo- and chloro-acetic acids altered embryonic development when mouse conceptuses were directly exposed to these xenobiotics in whole embryo culture...

  10. Metabolism, Microflora Effects, and Genotoxicity in Haloacetic Acid-Treated Cultures of Rat Cecal Microbiota

    Microsoft Academic Search

    G. M. Nelson; A. E. Swank; L. R. Brooks; K. C. Bailey; S. E. George

    2001-01-01

    Haloacetic acids are by-products of drinking water disinfection. Several compounds in this class are genotoxic and have been identi- fied as rodent hepatocarcinogens. Enzymes produced by the normal intestinal bacteria can transform some promutagens and procarcino- gens to their biologically active forms. The present study was de- signed to investigate the influence of the cecal microbiota on the mutagenicity of

  11. Determination of bromate and chlorinated haloacetic acids in bottled drinking water with chromatographic methods

    Microsoft Academic Search

    Yongjian Liu; Shifen Mou

    2004-01-01

    Disinfection by-products of interest such as bromate, chlorate and chlorinated haloacetic acids in 10 representative brands of bottled drinking water were investigated with ion chromatography. With the developed method, the detection limits of the disinfection by-products were in sub-?gl?1 level. It was observed that bromate, chlorate and dichloroacetic acid could be detected in some water samples. In the bottled natural

  12. Simultaneous determination of trace oxyhalides and haloacetic acids using suppressed ion chromatography-electrospray mass spectrometry

    Microsoft Academic Search

    Leon Barron; Brett Paull

    2006-01-01

    A new analytical procedure for the simultaneous determination of trace oxyhalides and haloacetic acids (HAs) in drinking water and aqueous soil extracts is described. The method uses micro-bore ion chromatography (IC) coupled with suppressed conductivity (SC) and electrospray ionization mass spectrometric detection (ESI-MS). The IC–SC–ESI-MS system included a secondary flow of 100% MeOH, which was added to the column eluate

  13. Using ion chromatography to monitor haloacetic acids in drinking water: a review of current technologies

    Microsoft Academic Search

    Brett Paull; Leon Barron

    2004-01-01

    A review of the application of ion chromatography to the determination of haloacetic acids in drinking water is given. As it requires no sample derivatisation, ion chromatography in its various modes, such as ion-exchange, ion-interaction and ion-exclusion chromatography, is increasingly being investigated as a simpler alternative to gas chromatographic methods for the determination of polar disinfection by-products (DBPs) in drinking

  14. DETERMINATION OF BROMATE IN THE PRESENCE OF BROMINATED HALOACETIC ACIDS BY ION CHROMATOGRAPHY WITH INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRIC DETECTION

    EPA Science Inventory

    Bromate is a disinfection by product (DBP) in drinking water that is formed during the ozonation of a source water containing bromide. Brominated haloacetic acids are DBPs that are anions at near -neutral phs. The anion character of bromoacetic acid (pKa=2.7) is similar to bromat...

  15. High performance ion chromatography of haloacetic acids on macrocyclic cryptand anion exchanger.

    PubMed

    Bruzzoniti, Maria Concetta; De Carlo, Rosa Maria; Horvath, Krisztian; Perrachon, Daniela; Prelle, Ambra; Tófalvi, Renáta; Sarzanini, Corrado; Hajós, Péter

    2008-04-11

    A new high performance ion chromatographic method has been developed for the separation of the nine chlorinated-brominated haloacetic acids (HAAs) that are the disinfection by-products of chlorination of drinking water, using a macrocycle-based adjustable-capacity anion-exchange separator column (IonPac Cryptand A1). A gradient method based on theoretical and experimental considerations has been optimized in which 10 mM NaOH-LiOH step gradient was performed at the third minute of the analysis. The optimized method allowed us to separate the nine HAAs and seven possibly interfering inorganic anions in less than 25 min with acceptable resolution. The minimum concentrations detectable for HAAs were between 8.0 (MBA) and 210 (TBA) microg L(-1), with linearity included between 0.9947 (TBA) and 0.9998 (MBA). To increase sensitivity, a 25-fold preconcentration step on a reversed phase substrate (LiChrolut EN) has been coupled. Application of this method to the analysis of haloacetic acids in real tap water samples is illustrated. PMID:18304560

  16. Environmentally Realistic Mixtures of the Five Regulated Haloacetic Acids Exhibit Concentration-Dependent Departures from Dose Additivity

    EPA Science Inventory

    Disinfection of water decreases waterborne disease. Disinfection byproducts (DBPs) are formed by the reaction of oxidizing disinfectants with inorganic and organic materials in the source water. The U.S. EPA regulates five haloacetic acid (HAA) DBPs as a mixture. The objective ...

  17. The formation and distribution of haloacetic acids in copper pipe during chlorination.

    PubMed

    Li, Bo; Liu, Ruiping; Liu, Huijuan; Gu, Junnong; Qu, Jiuhui

    2008-03-21

    The formation and distribution of HAAs in copper pipe during chlorination was investigated. To determine the material influence of copper pipe, parallel experiments were performed in glass pipe. Results showed that there was no obvious difference between the sum of haloacetic acids (HAAs) and trihalomethanes (THMs) produced in copper pipe compared to that produced in glass pipe over a 12h period. However, significant differences were observed about the distribution of five haloacetic acids in copper pipe and in glass pipe. Relatively less trichloroacetic acid (TCAA) and more monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), dibromoacetic acid (DBAA) and trihalomethanes (THMs) were produced in copper pipe than those in glass pipe. Corrosion scale on the wall of copper pipe was analyzed using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The results showed the scales on the pipe surface mainly consisted of Cu2O, CuO and Cu (OH)2 or CuCO3. During 24h stagnation, copper released gradually from copper pipe. The influences of copper (II) and copper oxides on the distribution of HAAs were investigated in designed experiments. Results showed that less amount of TCAA, more amounts of DCAA and MCAA were formed with increasing concentration of copper (II). It was because the accelerative effect of copper (II) on the depletion of chlorination restricted the formation of TCAA precursor and the further formation of TCAA. Owing to the transformation of DCAA precursor to TCAA precursor was limited, more DCAA precursor could yield DCAA. The influences of Cu2O and CuO on the distribution of TCAA and DCAA were the result of copper released at higher content. PMID:17689009

  18. Determination of bromate and chlorinated haloacetic acids in bottled drinking water with chromatographic methods.

    PubMed

    Liu, Yongjian; Mou, Shifen

    2004-06-01

    Disinfection by-products of interest such as bromate, chlorate and chlorinated haloacetic acids in 10 representative brands of bottled drinking water were investigated with ion chromatography. With the developed method, the detection limits of the disinfection by-products were in sub-microgl(-1) level. It was observed that bromate, chlorate and dichloroacetic acid could be detected in some water samples. In the bottled natural water, the concentrations for the three compounds were 0.1, 0.9 and 0.6 microgl(-1), respectively. The total concentration of disinfection by-products in the natural water sample was the highest among all the bottled drinking waters. The concentrations for the sum of disinfection by-products in the four types of bottled drinking water investigated were natural water > mineral water > spring water > purified water. The generation of disinfection by-products was much influenced by the original components and process procedure of the source water. The concentrations of bromate and chlorate in the bottled water samples hardly degraded with the increasing storage time. For dichloroacetic acid, with the prolonging of storage time, the concentration was much decreased. PMID:15081766

  19. Determination of haloacetic acids in aqueous environments by solid-phase extraction followed by ion-pair liquid chromatography–electrospray ionization mass spectrometric detection

    Microsoft Academic Search

    Robert Loos; Damià Barceló

    2001-01-01

    Haloacetic acids (HAAs) were determined in different water samples by a new, fast and simple analysis method based on enrichment of 50-ml water samples at pH 1.8 by solid-phase extraction (SPE) followed by liquid chromatography (LC) separation and electrospray ionization mass spectrometric detection in the negative ionization mode. Deprotonated (M-H)? haloacetates and decarboxylated (M-COOH)? ions were detected. Different polymeric SPE

  20. Simultaneous determination of trace oxyhalides and haloacetic acids using suppressed ion chromatography-electrospray mass spectrometry.

    PubMed

    Barron, Leon; Paull, Brett

    2006-05-15

    A new analytical procedure for the simultaneous determination of trace oxyhalides and haloacetic acids (HAs) in drinking water and aqueous soil extracts is described. The method uses micro-bore ion chromatography (IC) coupled with suppressed conductivity (SC) and electrospray ionization mass spectrometric detection (ESI-MS). The IC-SC-ESI-MS system included a secondary flow of 100% MeOH, which was added to the column eluate (post-suppressor) and resulted in a significant increase in sensitivity for all analytes. All ESI-MS parameters were optimized for HA analysis and sensitivity quantitatively compared to suppressed conductivity. Full analytical performance characteristics for the developed method are presented for monochloro-, monobromo-, dichloro-, dibromo-, trichloro-, bromochloro, chlorodifluoro-, trifluoro-, dichlorobromo- and dibromochloroacetic acid, as well as the oxyhalides iodate, bromate, chlorate and perchlorate. In the case of the HAs, an optimised 25-fold SPE preconcentration method meant all analytes could be readily detected well below the USEPA 60mug/L regulatory limit using conductivity and/or ESI-MS. The IC-ESI-MS method was applied to the determination of oxyhalides and HAs in both soil extracts and drinking water samples. Soil samples were extracted using ultra pure water with subsequent determination of perchlorate at 1.68mug/g of soil. A drinking water sample containing HAs was preconcentrated using LiChrolut EN solid phase extraction cartridges with subsequent sulphate and chloride removal. Total HAs were determined at 13mug/L. PMID:18970613

  1. Comparison of three-dimensional fluorescence analysis methods for predicting formation of trihalomethanes and haloacetic acids.

    PubMed

    Peleato, Nicolás M; Andrews, Robert C

    2015-01-01

    This work investigated the application of several fluorescence excitation-emission matrix analysis methods as natural organic matter (NOM) indicators for use in predicting the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Waters from four different sources (two rivers and two lakes) were subjected to jar testing followed by 24hr disinfection by-product formation tests using chlorine. NOM was quantified using three common measures: dissolved organic carbon, ultraviolet absorbance at 254 nm, and specific ultraviolet absorbance as well as by principal component analysis, peak picking, and parallel factor analysis of fluorescence spectra. Based on multi-linear modeling of THMs and HAAs, principle component (PC) scores resulted in the lowest mean squared prediction error of cross-folded test sets (THMs: 43.7 (?g/L)(2), HAAs: 233.3 (?g/L)(2)). Inclusion of principle components representative of protein-like material significantly decreased prediction error for both THMs and HAAs. Parallel factor analysis did not identify a protein-like component and resulted in prediction errors similar to traditional NOM surrogates as well as fluorescence peak picking. These results support the value of fluorescence excitation-emission matrix-principal component analysis as a suitable NOM indicator in predicting the formation of THMs and HAAs for the water sources studied. PMID:25597674

  2. Effect of the chlorinated washing of minimally processed vegetables on the generation of haloacetic acids.

    PubMed

    Cardador, Maria Jose; Gallego, Mercedes

    2012-07-25

    Chlorine solutions are usually used to sanitize fruit and vegetables in the fresh-cut industry due to their efficacy, low cost, and simple use. However, disinfection byproducts such as haloacetic acids (HAAs) can be formed during this process, which can remain on minimally processed vegetables (MPVs). These compounds are toxic and/or carcinogenic and have been associated with human health risks; therefore, the U.S. Environmental Protection Agency has set a maximum contaminant level for five HAAs at 60 ?g/L in drinking water. This paper describes the first method to determine the nine HAAs that can be present in MPV samples, with static headspace coupled with gas chromatography-mass spectrometry where the leaching and derivatization of the HAAs are carried out in a single step. The proposed method is sensitive, with limits of detection between 0.1 and 2.4 ?g/kg and an average relative standard deviation of ?8%. From the samples analyzed, we can conclude that about 23% of them contain at least two HAAs (<0.4-24 ?g/kg), which showed that these compounds are formed during washing and then remain on the final product. PMID:22747435

  3. Method of analysis at the U.S. Geological Survey California Water Science Center, Sacramento Laboratory - determination of haloacetic acid formation potential, method validation, and quality-control practices

    USGS Publications Warehouse

    Zazzi, Barbara C.; Crepeau, Kathryn L.; Fram, Miranda S.; Bergamaschi, Brian A.

    2005-01-01

    An analytical method for the determination of haloacetic acid formation potential of water samples has been developed by the U.S. Geological Survey California Water Science Center Sacramento Laboratory. The haloacetic acid formation potential is measured by dosing water samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine. The haloacetic acids formed are bromochloroacetic acid, bromodichloroacetic acid, dibromochloroacetic acid, dibromoacetic acid, dichloroacetic acid, monobromoacetic acid, monochloroacetic acid, tribromoacetic acid, and trichloroacetic acid. They are extracted, methylated, and then analyzed using a gas chromatograph equipped with an electron capture detector. Method validation experiments were performed to determine the method accuracy, precision, and detection limit for each of the compounds. Method detection limits for these nine haloacetic acids ranged from 0.11 to 0.45 microgram per liter. Quality-control practices include the use of blanks, quality-control samples, calibration verification standards, surrogate recovery, internal standard, matrix spikes, and duplicates.

  4. The fate of haloacetic acids and trihalomethanes in an aquifer storage and recovery program, Las Vegas, Nevada

    USGS Publications Warehouse

    Thomas, J.M.; McKay, W.A.; Colec, E.; Landmeyer, J.E.; Bradley, P.M.

    2000-01-01

    The fate of disinfection byproducts during aquifer storage and recovery (ASR) is evaluated for aquifers in Southern Nevada. Rapid declines of haloacetic acid (HAA) concentrations during ASR, with associated little change in Cl concentration, indicate that HAAs decline primarily by in situ microbial oxidation. Dilution is only a minor contributor to HAA concentration declines during ASR. Trihalomethane (THM) concentrations generally increased during storage of artificial recharge (AR) water and then declined during recovery. The decline of THM concentrations during recovery was primarily from dilution of current season AR water with residual AR water remaining in the aquifer from previous ASR seasons and native ground water. In more recent ASR seasons, for wells with the longest history of ASR, brominated THMs declined during storage and recovery by processes in addition to dilution. These conclusions about THMs are indicated by THM/Cl values and supported by a comparison of measured and model predicted THM concentrations. Geochemical mixing models were constructed using major-ion chemistry of the three end-member waters to calculate predicted THM concentrations. The decline in brominated THM concentrations in addition to that from dilution may result from biotransformation processes.

  5. Analysis of haloacetic acids in water and air (aerosols) from indoor swimming pools using HS-SPME/GC/ECD.

    PubMed

    Sá, Christopher S A; Boaventura, Rui A R; Pereira, Isabel B

    2012-01-01

    A solid phase microextraction method was used for the analysis of nine haloacetic acids (HAAs) in water and air (aerosols) from indoor swimming pools (ISPs). The analysis is characterized by derivatization of HAAs to their methyl-esters with dimethyl sulphate, headspace solid phase microextraction (HS-SPME) with a Carboxen-polydimethylsiloxane (CAR-PDMS) fiber and gas chromatography - electron capture detector (GC/ECD). High correlation coefficients were obtained for esters mixture calibration lines and detection limits were found to be at the low ppb level. Repeatability was assessed and coefficients of variation varied from 10 to 20%. Reproducibility was also evaluated and coefficients of variation from 15 to 25% were obtained. Analytical results from four Portuguese ISPs showed that the mean concentration of total HAAs (THAAs) in water ranged from 10 ± 2 to 183 ± 28 ?g/L in which 55 ± 20% corresponded to trichloroacetic and dichloroacetic acids (TCAA and DCAA). THAAs highest concentrations were directly related to higher ISPs' water organic matter content. In the lack of European specific regulation for water from ISPs and taking into consideration that ingestion is a form of exposure, THAAs concentration values were compared with drinking water maximum contamination level (MCL) of 60 ?g/L proposed by the US EPA for the sum of five HAAs. In 35% of water sampling campaigns the sum of MBAA (monobromoacetic acid), MCAA (monochloroacetic acid), DCAA and TCAA exceeded that MCL value. The concentrations obtained for THAAs in the ISPs' atmosphere ranged from 5 ± 1 to 64 ± 10 ?g/m(3) (T = 28°C at 5 cm above the water surface) and were proportional to the aerosols' quantity, which was deeply related to indoor air ventilation system. PMID:22242869

  6. 40 CFR 141.64 - Maximum contaminant levels for disinfection byproducts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration...

  7. 40 CFR 141.64 - Maximum contaminant levels for disinfection byproducts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration...

  8. 40 CFR 141.64 - Maximum contaminant levels for disinfection byproducts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration...

  9. 40 CFR 141.64 - Maximum contaminant levels for disinfection byproducts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration...

  10. 40 CFR 141.64 - Maximum contaminant levels for disinfection byproducts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary...TTHM) and Haloacetic acids (five) (HAA5) Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration...

  11. GAS CHROMATOGRAPHY/MASS SPECTROMETRY STUDY OF MIXED HALOACETIC ACIDS FOUND IN CHLORINATED DRINKING WATER

    EPA Science Inventory

    Over the last two years, our laboratory and others have identified mono-, di-, and trichloro- acetic acids as major byproducts of drinking water disinfection. n areas of the country where relatively high levels of bromine ion are naturally present in the source water, it is expec...

  12. Simultaneous determination of bromate, chlorite and haloacetic acids by two-dimensional matrix elimination ion chromatography with coupled conventional and capillary columns.

    PubMed

    Teh, Hui Boon; Li, Sam Fong Yau

    2015-02-27

    A new, highly sensitive and reliable two-dimensional matrix elimination ion chromatography (IC) method was developed for simultaneous detection of bromate, chlorite and five haloacetic acids. This method combined the conventional IC in first dimension with capillary IC in the second dimension coupled with suppressed conductivity detection. The first dimension utilizes a high capacity column to partially resolve matrix from target analytes. By optimizing the cut window, the target analytes were selectively cut and trapped in a trap column through the use of a six-port valve, while the separated matrix were diverted to waste. The trapped target analytes were delivered on to the capillary column for further separation and detection. Temperature programming was used to improve selectivity in second dimension column to obtain complete resolution of the target analytes. Compared to the performance of one-dimensional IC, the two-dimensional approach resulted in a significant increase in sensitivity for all target analytes with limit of detection ranging from 0.30 to 0.64?g/L and provided more reliable analysis due to second column confirmation. Good linearity was obtained for all the target analytes with correlation coefficients >0.998. The proposed method was successfully applied to the determination of oxyhalides and haloacetic acids in various matrices with recoveries ranging from 90 to 116% and RSD less than 6.1%. The method allows direct injection of samples and the use of columns with different selectivity, thus significantly reduces the level of false positive results. The method is fully automated and simple, making it practical for routine monitoring of water quality. The satisfactory results also demonstrated that the two-dimensional matrix elimination method coupled with capillary IC is a promising approach for detection of trace substances in complex matrices. PMID:25650354

  13. An Optimized Analytical Method for the Simultaneous Detection of Iodoform, Iodoacetic Acid, and Other Trihalomethanes and Haloacetic Acids in Drinking Water

    PubMed Central

    Jiang, Songhui; Templeton, Michael R.; He, Gengsheng; Qu, Weidong

    2013-01-01

    An optimized method is presented using liquid-liquid extraction and derivatization for the extraction of iodoacetic acid (IAA) and other haloacetic acids (HAA9) and direct extraction of iodoform (IF) and other trihalomethanes (THM4) from drinking water, followed by detection by gas chromatography with electron capture detection (GC-ECD). A Doehlert experimental design was performed to determine the optimum conditions for the five most significant factors in the derivatization step: namely, the volume and concentration of acidic methanol (optimized values ?=?15%, 1 mL), the volume and concentration of Na2SO4 solution (129 g/L, 8.5 mL), and the volume of saturated NaHCO3 solution (1 mL). Also, derivatization time and temperature were optimized by a two-variable Doehlert design, resulting in the following optimized parameters: an extraction time of 11 minutes for IF and THM4 and 14 minutes for IAA and HAA9; mass of anhydrous Na2SO4 of 4 g for IF and THM4 and 16 g for IAA and HAA9; derivatization time of 160 min and temperature at 40°C. Under optimal conditions, the optimized procedure achieves excellent linearity (R2 ranges 0.9990–0.9998), low detection limits (0.0008–0.2 µg/L), low quantification limits (0.008–0.4 µg/L), and good recovery (86.6%–106.3%). Intra- and inter-day precision were less than 8.9% and 8.8%, respectively. The method was validated by applying it to the analysis of raw, flocculated, settled, and finished waters collected from a water treatment plant in China. PMID:23613747

  14. Direct injection ion chromatography for the control of chlorinated drinking water: simultaneous estimation of nine haloacetic acids and quantitation of bromate, chlorite and chlorate along with the major inorganic anions.

    PubMed

    Garcia-Villanova, Rafael J; Raposo Funcia, César; Oliveira Dantas Leite, M Vilani; Toruño Fonseca, Ivania M; Espinosa Nieto, Miguel; Espuelas India, Javier

    2014-09-01

    Most methods for the analysis of haloacetic acids published in recent years are based on ion chromatography with direct injection, employing a gradient elution with potassium hydroxide (KOH). This work reports the exploration of an alternative eluent, a buffer of sodium carbonate/sodium hydrogen carbonate, aimed at the simultaneous analysis of nine haloacetic acids along with bromate, chlorite and chlorate. The alternative of both a less alkaline eluent and a lower temperature of operation may prevent the partial decomposition of some of the haloacetic acids during the analytical process, especially the more vulnerable brominated ones. Gradient elution at temperature of 7 °C yielded the best results, with an acceptable separation of 17 analytes (which includes the major natural inorganic anions) and a good linearity. Precision ranges from 0.3 to 23.4 (% V.C.), and detection limits are within units of ?g L?¹, except for tribromoacetic acid - somewhat high in comparison with those of the official methods. Nonetheless, with the basic instrumentation setup herein described, this method may be suitable for monitoring when the drinking water treatments are to be optimized. This is especially interesting for small communities or for developing/developed countries in which regulations on disinfection by-products others than trihalomethanes are being addressed. PMID:25252348

  15. Determination of haloacetic acids in bottled and tap water sources by dispersive liquid-liquid microextraction and GC-MS analysis.

    PubMed

    Al-shatri, Mohsen A; Nuhu, Abdulmumin A; Basheer, Chanbasha

    2014-01-01

    Haloacetic acids are toxic organic pollutants that can be formed as by-products of disinfection of water by chlorination. In this study, we developed a fast and efficient method for the determination of six species of these compounds in water using dispersive liquid-liquid microextraction followed by GC-MS analysis. To be suitable for GC analysis, the acidic analytes were derivatized using n-octanol. One-factor-at-a-time optimization was carried out on several factors including temperature, extraction time, amount of catalyst, and dispersive solvent. The optimized conditions were then used to determine calibration parameters. Linearity, as demonstrated by coefficient of determination, ranged between 0.9900 and 0.9966 for the concentration range of 0.05-0.57 µg/L. The proposed method has good repeatability; intraday precision was calculated as %RSD of 2.38-9.34%, while interday precision was 4.69-8.06%. The method was applied to real samples in bottled water and tap water sources. Results indicated that the total concentrations of the analytes in these sources (2.97-5.30 µg/L) were far below the maximum contaminant levels set by both the World Health Organization and the United States Environmental Protection Agency. The proposed method compared favorably with methods reported in the literature. PMID:25295305

  16. Determination of Haloacetic Acids in Bottled and Tap Water Sources by Dispersive Liquid-Liquid Microextraction and GC-MS Analysis

    PubMed Central

    Al-shatri, Mohsen A.; Nuhu, Abdulmumin A.; Basheer, Chanbasha

    2014-01-01

    Haloacetic acids are toxic organic pollutants that can be formed as by-products of disinfection of water by chlorination. In this study, we developed a fast and efficient method for the determination of six species of these compounds in water using dispersive liquid-liquid microextraction followed by GC-MS analysis. To be suitable for GC analysis, the acidic analytes were derivatized using n-octanol. One-factor-at-a-time optimization was carried out on several factors including temperature, extraction time, amount of catalyst, and dispersive solvent. The optimized conditions were then used to determine calibration parameters. Linearity, as demonstrated by coefficient of determination, ranged between 0.9900 and 0.9966 for the concentration range of 0.05–0.57?µg/L. The proposed method has good repeatability; intraday precision was calculated as %RSD of 2.38–9.34%, while interday precision was 4.69–8.06%. The method was applied to real samples in bottled water and tap water sources. Results indicated that the total concentrations of the analytes in these sources (2.97–5.30?µg/L) were far below the maximum contaminant levels set by both the World Health Organization and the United States Environmental Protection Agency. The proposed method compared favorably with methods reported in the literature. PMID:25295305

  17. Pyruvate Remediation of Cell Stress and Genotoxicity Induced by Haloacetic Acid Drinking Water Disinfection By-Products

    PubMed Central

    Dad, Azra; Jeong, Clara H.; Pals, Justin A.; Wagner, Elizabeth D.; Plewa, Michael J.

    2014-01-01

    Monohaloacetic acids (monoHAAs) are a major class of drinking water disinfection by-products (DBPs) and are cytotoxic, genotoxic, mutagenic, and teratogenic. We propose a model of toxic action based on monoHAA-mediated inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a target cytosolic enzyme. This model predicts that GAPDH inhibition by the monoHAAs will lead to a severe reduction of cellular ATP levels and repress the generation of pyruvate. A loss of pyruvate will lead to mitochondrial stress and genomic DNA damage. We found a concentration-dependent reduction of ATP in Chinese hamster ovary cells after monoHAA treatment. ATP reduction per pmol monoHAA followed the pattern of iodoacetic acid (IAA) > bromoacetic acid (BAA) >> chloroacetic acid (CAA), which is the pattern of potency observed with many toxicological endpoints. Exogenous supplementation with pyruvate enhanced ATP levels and attenuated monoHAA-induced genomic DNA damage as measured with single cell gel electrophoresis. These data were highly correlated with the SN2 alkylating potentials of the monoHAAs and with the induction of toxicity. The results from this study strongly support the hypothesis that GAPDH inhibition and the possible subsequent generation of reactive oxygen species is linked with the cytotoxicity, genotoxicity, teratogenicity, and neurotoxicity of these DBPs. PMID:23893730

  18. Influence of soluble microbial products (SMP) on wastewater disinfection byproducts: trihalomethanes and haloacetic acid species from the chlorination of SMP

    Microsoft Academic Search

    Yuan-yuan Wei; Yan Liu; Yun Zhang; Rui-hua Dai; Xiang Liu; Jin-jian Wu; Qiang Zhang

    2011-01-01

    Introduction  Effluent organic matter from biological wastewater treatment plants is composed of degradation products and soluble microbial\\u000a products (SMP). Protein, polysaccharide, humic acid, and DNA were major biomolecules of SMP. Little is known about the effects\\u000a of SMP as microbially derived precursors on disinfection byproduct formation and speciation in biologically treated wastewater.\\u000a In addition, there has never been any attempt to

  19. 40 CFR 141.628 - Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.628 Requirements for remaining on increased TTHM and HAA5 monitoring based on...

  20. 40 CFR 141.627 - Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.627 Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart...

  1. 40 CFR 141.627 - Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.627 Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart...

  2. 40 CFR 141.627 - Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.627 Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart...

  3. 40 CFR 141.628 - Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.628 Requirements for remaining on increased TTHM and HAA5 monitoring based on...

  4. 40 CFR 141.627 - Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.627 Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart...

  5. 40 CFR 141.628 - Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.628 Requirements for remaining on increased TTHM and HAA5 monitoring based on...

  6. 40 CFR 141.628 - Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.628 Requirements for remaining on increased TTHM and HAA5 monitoring based on...

  7. 40 CFR 141.628 - Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.628 Requirements for remaining on increased TTHM and HAA5 monitoring based on...

  8. 40 CFR 141.627 - Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection Byproducts Requirements § 141.627 Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart...

  9. Chronic Exposure to Dibromoacetic Acid, a Water Disinfection Byproduct, Diminishes Primordial Follicle Populations in the Rabbit

    Microsoft Academic Search

    K. J. Bodensteiner; H. R. Sawyer; C. L. Moeller; C. M. Kane; K.-Y. F. Pau; G. R. Klinefelter; D. N. R. Veeramachaneni

    2004-01-01

    Haloacetic acids are formed during the process of water disin- fection when chlorinated or brominated products used to disin- fect water react with organics and bromine in source water. By weight, haloacetic acids are among the most abundant water disinfection byproducts and are a prominent concern from a health and regulatory standpoint (Uden and Miller, 1983). Cer- tain haloacetic acids,

  10. 40 CFR 141.620 - General requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...achieving compliance with maximum contaminant levels based on locational running annual averages (LRAA) for total trihalomethanes (TTHM) and haloacetic acids (five)(HAA5), and for achieving compliance with maximum residual...

  11. Application of Magnetized Anion Exchange Resin for Removal of DOC at Coldiron Watkins Memorial Water Treatment Plant in Danville, KY

    Microsoft Academic Search

    Elizabeth Hamm; Michael Bourke

    According to data gathered by the Information Collection Rule1, surface water treatment plants (SWTPs) can expect treated-water total haloacetic acid concentrations to be less than total trihalomethane (TTHM) concentrations. However, many SWTPs are plagued with distribution system haloacetic acid (HAA5) concentrations that are higher than TTHM concentrations. The 10 million gallons per day (MGD) Coldiron Watkins Memorial Water Treatment Plant

  12. MIXING RATIO INFLUENCES HALOACETIC ACID (HAA) MIXTURE TOXICITY

    EPA Science Inventory

    Mixtures of the same type (for example, disinfection byproduct mixtures) often contain the same chemicals, but at varying concentrations. The objective of the present study was to examine the influence of mixing ratio (the concentrations of chemicals relative to one another) on ...

  13. FORMATION AND ENANTIOSELECTIVE BIODEGRADATION OF THE ENANTIOMERS OF BROMOCHLOROACETIC ACID

    EPA Science Inventory

    Bromochloroacetic acid (BCAA) is formed by chlorination of drinking waters containing naturally occurring bromide. This haloacetic acid is a concern to public health because of suspected carcinogenicity and toxicity, and is a potential target of disinfectant byproduct regulations...

  14. DRINKING WATER DISINFECTION BYPRODUCTS AND DURATION OF GESTATION

    EPA Science Inventory

    Recent studies of drinking water disinfection by-products (DBPs) suggest high exposure decreases risk of preterm birth. We examined this association with total trihalomethane (TTHM) and five haloacetic acids (HAA5) among 2,041 women in a prospective pregnancy study conducted from...

  15. Evaluate HAA removal in biologically active carbon filters using the ICR database

    Microsoft Academic Search

    Hsin-hsin Tung; Yuefeng F. Xie

    The effects of biologically active carbon (BAC) filtration on haloacetic acid (HAA) levels in plant effluents and distribution\\u000a systems were investigated using the United States Environmental Protection Agency’s Information Collection Rule (ICR) database.\\u000a The results showed that average HAA5 concentrations in all locations were 20.4 ?g·L?1 and 29.6 ?g·L?1 in ICR plants with granular activated carbon (GAC) and ICR plants

  16. HALOACETONITRILES VS. REGULATED HALOACETIC ACIDS: ARE NITROGEN CONTAINING DBPS MORE TOXIC?

    EPA Science Inventory

    Haloacetonitriles (HANs) are toxic nitrogenous drinking water disinfection by-products (N-DBPs) and are observed with chlorine, chloramine, or chlorine dioxide disinfection. Using microplate-based Chinese hamster ovary (CHO) cell assays for chronic cytotoxicity and acute genotoxi...

  17. INHALATION EXPOSURE TO HALOACETIC ACIDS AND HALOKETONES DURING SHOWERING. (R825953)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  18. DIBROMOACETIC ACID-INDUCED ELEVATIONS OF ESTRADIOL IN THE CYCLING AND OVARIECTOMOZED/ESTRADIOL-IMPLANTED FEMALE RAT

    EPA Science Inventory

    Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations of Estradiol in Both Cycling and Ovariectomized / Estradiol-implanted Female Rats ABSTRACT Haloacetic acids are one of the principal classes of disinfection by-products generated by the chlorination of mun...

  19. ALTERED CRANIOFACIAL GENE EXPRESSION OF NEURULATION STAGED MOUSE EMBRYO CULTURES EXPOSED TO BROMOCHLOROACETIC ACID

    EPA Science Inventory

    An unintended consequence of chemical disinfection of municipal drinking water is the production of chemical disinfection by-products (DBPs). A major class ofDBPs are haloacetic acidsthat may be found at concentrations higher than other DBPs. Bromochloroacetic acid (BCA) is a de...

  20. EVALUATION OF THE JOINT TOXIC ACTION OF MIXTURES OF HALOACETIC ACIDS CONSTRUCTED USING ENVIRONMENTAL CONCENTRATION/EXPOSURE DATA

    EPA Science Inventory

    Disinfection byproducts (DBPs) are formed by reactions between chemicals used to disinfect water and organic compounds present in source water. The composition of DBP mixtures varies based on a number of factors, including treatment scenario, with different DBP mixtures contain...

  1. Yield of trihalomethanes and haloacetic acids upon chlorinating algal cells, and its prediction via algal cellular biochemical composition

    Microsoft Academic Search

    Hua Chang Hong; Asit Mazumder; Ming Hung Wong; Yan Liang

    2008-01-01

    The major objective of the present study was to investigate the contribution of major biomolecules, including protein, carbohydrates and lipids, in predicting DBPs formation upon chlorination of algal cells. Three model compounds, including bovine serum albumin (BSA), starch and fish oil, as surrogates of algal-derived proteins, carbohydrates and lipids, and cells of three algae species, representing blue-green algae, green algae,

  2. Disinfection byproduct formation resulting from settled, filtered, and finished water treated by titanium dioxide photocatalysis.

    PubMed

    Mayer, Brooke K; Daugherty, Erin; Abbaszadegan, Morteza

    2014-12-01

    This study evaluated strategies targeting disinfection byproduct (DBP) mitigation using TiO2 photocatalysis with varying influent water quality. A Purifics Photo-CAT Lab reactor was used to assess total trihalomethane (TTHM) and haloacetic acid (HAA) formation as a function of photocatalytic treatment using water from a conventional coagulation/flocculation/sedimentation process, granular activated carbon filtration, and a DBP hot spot in the water distribution system. Regardless of influent water quality, photocatalysis reduced DBP precursors; however, low-energy limited photocatalysis (<5 kW h m(-3)), exacerbated the production of TTHMs and HAA5s beyond initial levels. Accordingly, limited photocatalysis is not a suitable option when TTHMs and HAA5s are a concern, regardless of the level of pretreatment. Limited photocatalysis yields incomplete oxidation, wherein larger, more aromatic, humic organic compounds are broken into smaller molecular weight, less aromatic, and less humic moieties, which have considerable potential to produce DBPs. More complete mineralization of DBP precursors is obtained using extended photocatalysis (80-160 kW h m(-3)), which substantially decreases DBP precursors as well as TTHM and HAA5 concentrations. In order to balance DBP mitigation, energy, and chemical usage, targeted use of TiO2 photocatalysis is necessary in a water treatment train (e.g., extended photocatalysis at a distribution system hot spot, where the volumetrically high energy requirements may be justifiable). PMID:24972073

  3. EVALUATION OF THE CYTOTOXICITY OF DRINKING WATER DISINFECTION BYPRODUCTS (DBPS): TRIHALOMETHANES (THMS), HALONITROMETHANES (HNMS), AND HALOACETIC ACIDS (HAAS) IN NORMAL HUMAN COLON CELLS

    EPA Science Inventory

    Epidemiological studies have linked the consumption of chlorinated surface waters to an increased risk of colorectal cancer. THMs and HAAs were found to increase cancer in laboratory animals, but no toxicity studies exist for the recently identified HNMs. Normal Human colonocytes...

  4. Disinfection byproduct formation during biofiltration cycle: Implications for drinking water production.

    PubMed

    Delatolla, R; Séguin, C; Springthorpe, S; Gorman, E; Campbell, A; Douglas, I

    2015-10-01

    The goal of this study was to investigate the potential of biofiltration to reduce the formation potential of disinfection byproducts (DBPs). Particularly, the work investigates the effect of the duration of the filter cycle on the formation potential of total trihalomethanes (TTHM) and five species of haloacetic acids (HAA5), dissolved oxygen (DO), organic carbon, nitrogen and total phosphorous concentrations along with biofilm coverage of the filter media and biomass viability of the attached cells. The study was conducted on a full-scale biologically active filter, with anthracite and sand media, at the Britannia water treatment plant (WTP), located in Ottawa, Ontario, Canada. The formation potential of both TTHMs and HAA5s decreased due to biofiltration. However the lowest formation potentials for both groups of DBPs and or their precursors were observed immediately following a backwash event. Hence, the highest percent removal of DBPs was observed during the early stages of the biofiltration cycle, which suggests that a higher frequency of backwashing will reduce the formation of DBPs. Variable pressure scanning electron microscopy (VPSEM) analysis shows that biofilm coverage of anthracite and sand media increases as the filtration cycle progressed, while biomass viability analysis demonstrates that the percentage of cells attached to the anthracite and sand media also increases as the filtration cycle progresses. These results suggest that the development and growth of biofilm on the filters increases the DPB formation potential. PMID:26002158

  5. Synthesis of hydroxyeicosatetraenoic acids (HETE's) by adrenal glomerulosa cells and incorporation into cellular lipids

    SciTech Connect

    Campbell, W.B.; Richards, C.F.; Brady, M.T.; Falck, J.R.

    1986-03-05

    The role of lipoxygenase metabolites of arachidonic acid (AA) in the regulation of aldosterone secretion was studied in isolated rat adrenal glomerulosa cells. Cells were incubated with /sup 14/C-AA in the presence of angiotensin (AII). The media was extracted, metabolites isolated by HPLC, and structures of the metabolites determined by UV absorbance and mass spectrometry. The major products were 12- and 15-HETE with lesser amounts of 11- and 5-HETE. When adrenal cells were incubated with 15-, 12- or 5-HPETE or their respective HETE's (0.03-300nM), there was no significant change in basal or AII-stimulated aldosterone release. Cells were incubated with (/sup 3/H)-AA, -5-HETE, -15-HETE, -12-HETE or -LTB. The cellular lipids were extracted and analyzed by TLC. AA was incorporated into phospholipids (22%), cholesterol esters (50%) and triglycerides (21%). Neither the HETE's or LTB/sub 4/ were incorporated into phospholipids. 5-HETE was taken up into di- and mono-glycerides. The rates of incorporation of AA and 5-HETE were similar (+ 1/2 = 10 min). The incorporation of 5-HETE into glycerol esters did not modify the release of aldosterone by the cells. Thus, while adrenal cells synthesize HETE's, these eicosanoids do not appear to alter the synthesis of aldosterone.

  6. Late Pregnancy Exposures to Disinfection By-products and Growth-Related Birth Outcomes

    PubMed Central

    Hinckley, Alison F.; Bachand, Annette M.; Reif, John S.

    2005-01-01

    Toxicologic studies have demonstrated associations between growth-related birth outcomes and exposure to high concentrations of disinfection by-products (DBPs), including specific tri-halomethane (THM) and haloacetic acid (HAA) chemical subspecies. Few prior investigations of DBPs have evaluated exposure during the third trimester of pregnancy, the time period of gestation when fetal growth may be most sensitive to environmental influences. We conducted a retrospective cohort study to examine the effects of exposure to THMs and HAAs during the third trimester and during individual weeks and months of late gestation on the risks for term low birth weight, intrauterine growth retardation, and very preterm and preterm births. The study population (n = 48,119) included all live births and fetal deaths occurring from January 1998 through March 2003 to women whose residence was served by one of three community water treatment facilities. We found evidence of associations between exposure to specific HAAs and term low birth weight as well as intrauterine growth retardation and for exposure to the five regulated HAAs (HAA5) and term low birth weight. Our findings suggest a critical window of exposure with respect to fetal development during weeks 33–40 for the effects of dibromoacetic acid and during weeks 37–40 for the effects of dichloroacetic acid. Adjustment for potential confounders did not affect the conclusions. PMID:16330369

  7. Source Water Management for Disinfection By-Product Control using New York City's Operations Support Tool and On-Line Monitoring

    NASA Astrophysics Data System (ADS)

    Weiss, W. J.; Becker, W.; Schindler, S.

    2012-12-01

    The United States Environmental Protection Agency's 2006 Stage 2 Disinfectant / Disinfection Byproduct Rule (DBPR) for finished drinking waters is intended to reduce overall DBP levels by limiting the levels of total trihalomethanes (TTHM) and five of the haloacetic acids (HAA5). Under Stage 2, maximum contaminant levels (MCLs), 80 ?g/L for TTHM and 60 ?g/L for HAA5, are based on a locational running annual average for individual sites instead of as the system-wide quarterly running annual average of the Stage 1 DBPR. This means compliance will have to be met at sampling locations of peak TTHM and HAA5 concentrations rather than an average across the entire system. Compliance monitoring under the Stage 2 DBPR began on April 1, 2012. The New York City (NYC) Department of Environmental Protection (DEP) began evaluating potential impacts of the Stage 2 DBPR on NYC's unfiltered water supply in 2002 by monitoring TTHM and HAA5 levels at various locations throughout the distribution system. Initial monitoring indicated that HAA5 levels could be of concern in the future, with the potential to intermittently violate the Stage 2 DBPR at specific locations, particularly those with high water age. Because of the uncertainty regarding the long-term prospect for compliance, DEP evaluated alternatives to ensure compliance, including operational changes (reducing chlorine dose, changing flow configurations to minimize water age, altering pH, altering source water withdrawals); changing the residual disinfectant from free chlorine to chloramines; and engineered treatment alternatives. This paper will discuss the potential for using DEP's Operations Support Tool (OST) and enhanced reservoir monitoring to support optimization of source water withdrawals to minimize finished water DBP levels. The OST is a state-of-the-art decision support system (DSS) to provide computational and predictive support for water supply operations and planning. It incorporates a water supply system simulation model (OASIS, HydroLogics, Inc.), reservoir water quality models, a near real-time monitoring network, and hydrologic forecasts to provide analytical support for both long-term planning and near-term operations. The OST helps managers and operators balance multiple objectives, including water supply reliability, water quality, and environmental and community release objectives. This paper will describe the results of initial testing to evaluate the potential to reduce DBP levels by managing source water withdrawals to minimize the transport of natural organic matter (NOM) precursors from upper reservoirs. Operating rules were developed that take advantage of selective withdrawal capabilities at some upstate reservoirs and the inherent flexibility of the overall water supply system, seeking to minimize DBPs within the larger framework of water supply, water quality, environmental, and regulatory objectives. The results demonstrated that there is substantial flexibility within the system to manage DBP levels, in some cases providing the potential for reductions of DBP precursors of nearly 10%. Additional research is underway that seeks to better understand the sources of natural organic matter in the NYC watershed to provide guidance for on-line monitoring to be used with the OST to support real-time operation support for DBP control.

  8. Control of disinfection by-product formation using ozone-based advanced oxidation processes.

    PubMed

    Chen, Kuan-Chung; Wang, Yu-Hsiang

    2012-01-01

    The effects of ozone dosage, water temperature and catalyst addition in an ozonation-fluidized bed reactor (O3/FBR) on treated water quality and on the control of chlorinated and ozonated disinfection by-products (DBPs) were investigated. A biofiltration column was used to evaluate its removal efficiency on biodegradable organic matter and to reduce DBP formation. The Dong-Gang River, polluted by agricultural and domestic wastewater in Pingtung, Taiwan, was used as the water source. The treated water quality in terms of dissolved organic carbon (DOC), biodegradable DOC, ultraviolet absorbance at 254 nm (UV254) and specific UV absorbance (SUVA) improved with increasing ozone and catalyst dosages. Catalytic ozonation was more effective than ozonation alone at reducing the formation of DBPs at a given dosage. Experimental results show that water temperature had little effect on the treated water quality with the O3/FBR system used in this study (p > 0.05). The combination of O3/FBR and the biofiltration process effectively decreased the amount ofDBP precursors. The concentration of total trihalomethanes (TTHMs) was less than the maximum contaminant level (MCL) requirement, which is 80 microg/L, for all treated waters and the concentration of five haloacetic acids (HAA5) fell below 60 microg/L with an ozone dosage higher than 2.5 mg/L. PMID:22629621

  9. 71 FR 388 - National Primary Drinking Water Regulations: Stage 2 Disinfectants and Disinfection Byproducts Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2006-01-04

    ...and benefit models using Monte Carlo probability functions. EPA believes this approach...HAA5 occurrence. EPA assigned equal probability to the 20 and 25 percent safety...Pereira. 1996. Loss of Heterozygosity on Chromosome 6 in Dichloroacetic Acid and...

  10. Peracetic acid oxidation of saline waters in the absence and presence of H ?O ?: secondary oxidant and disinfection byproduct formation.

    PubMed

    Shah, Amisha D; Liu, Zheng-Qian; Salhi, Elisabeth; Höfer, Thomas; von Gunten, Urs

    2015-02-01

    Peracetic acid (PAA) is a disinfectant considered for use in ballast water treatment, but its chemical behavior in such systems (i.e., saline waters) is largely unknown. In this study, the reactivity of PAA with halide ions (chloride and bromide) to form secondary oxidants (HOCl, HOBr) was investigated. For the PAA-chloride and PAA-bromide reactions, second-order rate constants of (1.47 ± 0.58) × 10(-5) and 0.24 ± 0.02 M(-1) s(-1) were determined for the formation of HOCl or HOBr, respectively. Hydrogen peroxide (H2O2), which is always present in PAA solutions, reduced HOCl or HOBr to chloride or bromide, respectively. As a consequence, in PAA-treated solutions with [H2O2] > [PAA], the HOBr (HOCl) steady-state concentrations were low with a limited formation of brominated (chlorinated) disinfection byproducts (DBPs). HOI (formed from the PAA-iodide reaction) affected this process because it can react with H2O2 back to iodide. H2O2 is thus consumed in a catalytic cycle and leads to less efficient HOBr scavenging at even low iodide concentrations (<1 ?M). In PAA-treated solutions with [H2O2] < [PAA] and high bromide levels, mostly brominated DBPs are formed. In synthetic water, bromate was formed from the oxidation of bromide. In natural brackish waters, bromoform (CHBr3), bromoacetic acid (MBAA), dibromoacetic acid (DBAA), and tribromoacetic acid (TBAA) formed at up to 260, 106, 230, and 89 ?g/L, respectively for doses of 2 mM (ca. 150 mg/L) PAA and [H2O2] < [PAA]. The same brackish waters, treated with PAA with [H2O2] ? [PAA], similar to conditions found in commercial PAA solutions, resulted in no trihalomethanes and only low haloacetic acid concentrations. PMID:25611970

  11. Quantitative detection of trichloroacetic acid in human urine using isotope dilution high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

    PubMed

    Kuklenyik, Zsuzsanna; Ashley, David L; Calafat, Antonia M

    2002-05-01

    The chemical disinfection of drinking water to control microbial contaminants results in the formation of disinfection byproducts (DBPs). The volatile trihalomethanes and the nonvolatile haloacetic acids (HAAs) are the most prevalent DBPs. It is important to monitor human exposure to HAAs because of their potential adversehealth effects, such as cancer. Among the HAAs, urinary trichloroacetic acid (TCAA) is a potential valid biomarker for assessing chronic ingestion exposure to HAAs from drinking water. We have developed a rugged, high-throughput, sensitive, accurate, and precise assay for the measurement of trace levels of TCAA in human urine using a simple solid-phase extraction (SPE) cleanup followed by isotope dilution high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). TCAA is extracted from the urine using SPE, separated from other extract components by reversed-phase HPLC, and analyzed by negative ion electrospray ionization-isotope dilution-MS/MS using a multiple reaction monitoring experiment. The method is simple and fast and is not labor intensive (sample preparation and analysis can be performed in approximately 15 min) with a limit of detection of 0.5 ng/mL in 1 mL of urine. PMID:12033307

  12. REPRODUCTIVE AND DEVELOPMENTAL EFFECTS SCREENING STUDIES

    EPA Science Inventory

    Several DBPs, particularly the disubstituted haloacetic acids (e.g. dibromoacetic acid, bromochloroacetic acid), have been shown to produce reproductive and developmental toxicity in laboratory animals. In 1993, an expert panel convened by the EPA and the International Life Scien...

  13. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  14. Aristolochic Acids

    MedlinePLUS

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  15. Use of urinary trichloroacetic acid as an exposure biomarker of disinfection by-products in cancer studies.

    PubMed

    Salas, Lucas A; Gracia-Lavedan, Esther; Goñi, Fernando; Moreno, Victor; Villanueva, Cristina M

    2014-11-01

    Urinary trichloroacetic acid (TCAA) has been proposed as a valid exposure biomarker for ingested disinfection by-products (DBP) for reproductive studies. However, it has never been used in epidemiologic studies on cancer. We investigate the performance of urinary TCAA as a biomarker of DBP exposure in the framework of an epidemiologic study on cancer. We conducted home visits to collect tap water, first morning void urine, and a 48h fluid intake diary among 120 controls from a case-control study of colorectal cancer in Barcelona, Spain. We measured urine TCAA and creatinine, and 9 haloacetic acids and 4 trihalomethanes (THM) in tap water. Lifetime THM exposure was estimated based on residential history since age 18 plus routine monitoring data. Robust linear regressions were used to estimate mean change in urinary TCAA adjusted by covariates. Among the studied group, mean age was 74 years (range 63-85) and 41 (34%) were females. Mean total tap water consumption was 2.2l/48h (standard error, 0.1l/48h). Geometric mean urine TCAA excretion rate was 17.3pmol/min [95%CI: 14.0-21.3], which increased 2% for a 10% increase in TCAA ingestion and decreased with total tap water consumption (-17%/l), water intake outside home (-32%), plasmatic volume (-64%/l), in smokers (-79%), and in users of non-steroidal anti-inflammatory drugs (-50%). Urinary TCAA levels were not associated with lifetime THM exposure. In conclusion, our findings support that urine TCAA is not a valid biomarker in case-control studies of adult cancer given that advanced age, comorbidites and medication use are prevalent and are determinants of urine TCAA levels, apart from ingested TCAA levels. In addition, low TCAA concentrations in drinking water limit the validity of urine TCAA as an exposure biomarker. PMID:25462676

  16. Rosmarinic acid.

    PubMed

    Petersen, Maike; Simmonds, Monique S J

    2003-01-01

    Rosmarinic acid is an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. It is commonly found in species of the Boraginaceae and the subfamily Nepetoideae of the Lamiaceae. However, it is also found in species of other higher plant families and in some fern and hornwort species. Rosmarinic acid has a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and antioxidant. The presence of rosmarinic acid in medicinal plants, herbs and spices has beneficial and health promoting effects. In plants, rosmarinic acid is supposed to act as a preformed constitutively accumulated defence compound. The biosynthesis of rosmarinic acid starts with the amino acids L-phenylalanine and L-tyrosine. All eight enzymes involved in the biosynthesis are known and characterised and cDNAs of several of the involved genes have been isolated. Plant cell cultures, e.g. from Coleus blumei or Salvia officinalis, accumulate rosmarinic acid in amounts much higher than in the plant itself (up to 36% of the cell dry weight). For this reason a biotechnological production of rosmarinic acid with plant cell cultures has been proposed. PMID:12482446

  17. Basically Acids

    NSDL National Science Digital Library

    University of Houston,

    Students learn the basics of acid/base chemistry in a fun, interactive way by studying instances of acid/base chemistry found in popular films such as Harry Potter and the Prisoner of Azkaban and National Treasure. Students learn what acids, bases and indicators are and how they can be used, including invisible ink. They also learn how engineers use acids and bases every day to better our quality of life. Students' interest is piqued by the use of popular culture in the classroom.

  18. Acid test

    NSDL National Science Digital Library

    Olivia Worland (Purdue University; Biological Sciences)

    2008-06-06

    Baking soda can be used as an indicator of how much acid a substance contains. Lemons and limes have more acid in them than grapefruits and oranges. Indophenol can be used as an indicator of how much vitamin C is in a substance.

  19. Acids (GCMP)

    NSDL National Science Digital Library

    Acids: this is a resource in the collection "General Chemistry Multimedia Problems". We will observe the reaction of sodium bicarbonate with three acid solutions. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

  20. Domoic Acid

    NSDL National Science Digital Library

    Bailey, Christina

    This online student report discusses the chemistry of domoic acid, a biotoxin that is produced by the diatom Psuedo-nitzschia and associated with Amnesiac Shellfish Poisoning (ASP). In addition to a descriptive summary and images, the report links to other areas of interest related to domoic acid poisoning including signs and symptoms, modes of action, and treatment.

  1. Acid rain

    SciTech Connect

    White, J.C. (Cornell University, Ithaca, NY (US))

    1988-01-01

    This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.

  2. Acid Rain

    Microsoft Academic Search

    Gene E. Likens; Richard F. Wright; James N. Galloway; Thomas J. Butler

    1979-01-01

    Measurements of the acidity of rain and snow reveal that in parts of the eastern U.S. and of western Europe precipitation has changed from a nearly neutral solution 200 years ago to a dilute solution of sulfuric and nitric acids today. The trend is a result of the emission of sulfur and nitrogen oxides to the atmosphere accompanying the rise

  3. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  4. Acid Precipitation

    NSDL National Science Digital Library

    Tyser, Jim

    Acid precipitation will be defined. At different points in the lesson students will write balanced reactions for the formation acid precipitation from atmospheric sulfur and nitrogen oxides and the neutralization of acids by limestone. Students will determine which states are most at risk from acid precipitation and assess how that risk has changed from 1996 to 2006. Sources of atmospheric sulfur (burning of high-sulfur coal) and nitrogen oxides (automobile exhaust) will be listed. The buffering effect of limestone soils and its mitigating effect on acid precipitation will be discussed. Students will correlate these areas with sulfur and nitrogen oxide production, population, composition of coal fields, and soil composition. This resource includes both a teaching guide and student worksheets.

  5. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for ?-lipoic acid in ?-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

  6. Folic Acid

    MedlinePLUS Videos and Cool Tools

    ... register. I'm interested in: Pregnancy Baby growth & care Research Volunteer opportunities Advocacy in government For health ... acid During your pregnancy Your pregnant body Prenatal care Eating and nutrition Physical activity Emotional and life ...

  7. ACID RAIN

    EPA Science Inventory

    Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...

  8. Carnosic acid.

    PubMed

    Birti?, Simona; Dussort, Pierre; Pierre, François-Xavier; Bily, Antoine C; Roller, Marc

    2015-07-01

    Carnosic acid (salvin), which possesses antioxidative and antimicrobial properties, is increasingly exploited within the food, nutritional health and cosmetics industries. Since its first extraction from a Salvia species (?70years ago) and its identification (?50years ago), numerous articles and patents (?400) have been published on specific food and medicinal applications of Rosmarinus and Salvia plant extracts abundant in carnosic acid. In contrast, relevant biochemical, physiological or molecular studies in planta have remained rare. In this overview, recent advances in understanding of carnosic acid distribution, biosynthesis, accumulation and role in planta, and its applications are summarised. We also discuss the deficiencies in our understanding of the relevant biochemical processes, and suggest the molecular targets of carnosic acid. Finally, future perspectives and studies related to its potential roles are highlighted. PMID:25639596

  9. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  10. IDENTIFICATION OF CHLORINE DIOXIDE DRINKING WATER DISINFECTION BY-PRODUCTS FORMED AT HIGH BROMIDE LEVELS

    EPA Science Inventory

    Due to concern over the potential adverse health effects of trihalomethanes (THMs), haloacetic acids, and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Chlorine dioxide is a popular alternative, with over 500 dri...

  11. DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by–products (DBPs) including total organic halide, trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along ...

  12. EARLY CRANIOFACIAL DEVELOPMENT: LIFE AMONG THE SIGNALS

    EPA Science Inventory

    Early Craniofacial Development: Life Among the Signals. Sid Hunter and Keith Ward. Reproductive Toxicology Division, NHEERL, US EPA, RTP, NC, 27711 Haloacetic acids (HAA) are chemicals formed during drinking water disinfection and present in finished tap water. Exposure o...

  13. FEASIBILITY STUDY OF THE UTILITY OF THE ICR DATABASE FOR STUDYING THE REPRODUCTIVE EFFECTS OF DISINFECTION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This study assessed the feasibility of conducting an epidemiologic study of the relationship between DBPs and adverse reproductive outcomes, using quarterly monitoring data of trihalomethanes and haloacetic acids from the EPA's Information Collection Rule (ICR) data base. Emphas...

  14. QUENCHING OF CHLORINATION DISINFECTION BY-PRODUCT FORMATION IN DRINKING WATER BY HYDROGEN PEROXIDE. (R825362)

    EPA Science Inventory

    Reactions between chlorine disinfectants, dissolved organic matter, and other chemicals in water form a series of disinfection by-products (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs), that are toxic and subject to increasingly stringent regulations. Th...

  15. HUMAN EXPOSURE TO WATER DISINFECTION BY-PRODUCTS VIA FOODS AND BEVERAGES

    EPA Science Inventory

    The ingestion of tap water is a major route of exposure to water disinfection byproducts (DBPs), including haloacetonitriles, haloketones, and haloacetic acids. A potentially significant alternate route of exposure is through the consumption of beverages prepared with tap water ...

  16. Acid Stomach

    NSDL National Science Digital Library

    Science Netlinks

    2003-08-07

    This Science NetLinks lesson is intended for a high-school, introductory chemistry class or health class. The lesson begins with an article on the history of the development of aspirin. Students will then complete a lab that compares the reaction of regular aspirin, buffered aspirin, and enteric aspirin in neutral, acidic, and basic solutions. They will then analyze the results of the experiment to gain insight into how this information was used by researchers to solve some of the problems associated with aspirin. To complete the lesson, students must understand acids and bases.

  17. Stearic Acid

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  18. Folic Acid

    MedlinePLUS

    ... lifelong disabilities. They may also need many surgeries. Anencephaly (an-en-SEF-uh-lee), which is when most or all of the brain does not develop. Babies with this problem die before or shortly after birth. The results of some studies suggest that folic acid might also help to prevent other types of ...

  19. Acid Rain

    NSDL National Science Digital Library

    This activity is part of Planet Diary and is an online examination into acid rain and sulfur dioxide emissions. Students research which states have succeeded in reducing sulfur dioxide emissions between 1980 and 1999, and which states emissions have increased. This activity is accompanied by a page of websites for further information.

  20. Acid Attack

    NSDL National Science Digital Library

    2014-09-18

    In this activity, students explore the effect of chemical erosion on statues and monuments. They use chalk to see what happens when limestone is placed in liquids with different pH values. They also learn several things that engineers are doing to reduce the effects of acid rain.

  1. Azelaic acid.

    PubMed

    Nazzaro-Porro, M

    1987-12-01

    This review is an update on the literature accumulated over the past 10 years following the original observation that azelaic acid, a naturally occurring and nontoxic C9 dicarboxylic acid, possesses significant biologic properties and a potential as a therapeutic agent. These studies have shown that azelaic acid is a reversible inhibitor of tyrosinase and other oxidoreductases in vitro and that it inhibits mitochondrial respiration. It can also inhibit anaerobic glycolysis. Both in vitro and in vivo it has an antimicrobial effect on both aerobic and anaerobic (Propionibacterium acnes) microorganisms. In tissue culture it exerts a dose- and time-dependent cytotoxic effect on malignant melanocytes, associated with mitochondrial damage and inhibition of deoxyribonucleic acid (DNA) synthesis. Tumoral cell lines not containing tyrosinase are equally affected. Normal cells in culture exposed to the same concentrations of the diacid that are toxic for tumoral cells are in general not damaged. Radioactive azelaic acid has been shown to penetrate tumoral cells at a higher level than normal cells of the corresponding line. Topically applied (a 20% cream), it has been shown to be of therapeutic value in skin disorders of different etiologies. Its beneficial effect on various forms of acne (comedogenic, papulopustular, nodulocystic) has been clearly demonstrated. Particularly important is its action on abnormal melanocytes, which has led to the possibility of obtaining good results on melasma and highly durable therapeutic responses on lentigo maligna. It is also capable of causing regression of cutaneous malignant melanoma, but its role in melanoma therapy remains to be investigated.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2963038

  2. Pharmacology of oleanolic acid and ursolic acid

    Microsoft Academic Search

    Jie Liu

    1995-01-01

    Oleanolic acid and ursolic acid are triterpenoid compounds that exist widely in food, medicinal herbs and other plants. This review summarizes the pharmacological studies on these two triterpenoids. Both oleanolic acid and ursolic acid are effective in protecting against chemically induced liver injury in laboratory animals. Oleanolic acid has been marketed in China as an oral drug for human liver

  3. Domoic Acid

    NSDL National Science Digital Library

    INCHEM

    This highly detailed chemical information page features domoic acid, a toxin associated with Amnesic shellfish poisoning and naturally produced by the red algae Chondria armata and diatoms of the genus Pseudo-nitzschia. Created by the International Programme on Chemical Safety, this web page organizes information under the following sections: Name, Summary, Physio-Chemical Properties, Uses, Routes of Entry, Kinetics, Toxicology, Toxicological and Biomedical Investigations, Clinical Effects, Management, Illustrative Cases, Additional Information, References, and Authors.

  4. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  5. New Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...

  6. Acid Ocean

    NSDL National Science Digital Library

    The I2I-Acid Ocean virtual lab is an e-learning activity where students become virtual scientists studying the impact of ocean acidification on sea urchin larval growth. Students recreate a real, up-to-date climate change experiment. They also learn important general scientific principles, such as the importance of sample size and numbers of replicates, and discuss what this research into a specific impact of climate change may mean for the future of our oceans. There is a French translation available.

  7. Brnsted Acids The Strongest Isolable Acid**

    E-print Network

    Reed, Christopher A.

    Brønsted Acids The Strongest Isolable Acid** Mark Juhasz, Stephan Hoffmann, Evgenii Stoyanov, Kee-Chan Kim, and Christopher A. Reed* Acids based on carborane anions as conjugate bases (Figure 1) are a new class of Brønsted (protic) acids, notable for their "strong yet gentle" qualities.[1] For example

  8. Acid rain

    SciTech Connect

    Boyle, R.H.; Boyle, R.A.

    1983-01-01

    Acid rain, says Boyle is a chemical leprosy eating into the face of North America and Europe, perhaps the major ecological problem of our time. Boyle describes the causes and scope of the phenomenon; the effects on man, wildlife, water, and our cultural heritage. He probes the delays of politicians and the frequent self-serving arguments advanced by industry in the face of what scientists have proved. The solutions he offers are to strengthen the Clean Air Act and require emission reductions that can be accomplished by establishing emission standards on a regional or bubble basis, burn low-sulfur coal, install scrubbers at critical plants, and invest in alternative energy sources. 73 references, 1 figure.

  9. Formic Acid Mechanical,

    E-print Network

    Illinois at Urbana-Champaign, University of

    Formic Acid Fire Ant Starch Mechanical, Industrial Chemical, Petroleum Biological What Do and engineering. Products will range from starch, to polylactic acid, to corn fiber, to motor fuels. Progressive systems. Fire ants make formic acid. U of I researchers are developing fuel cells that use formic acid (1

  10. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid

  11. Acids and Bases (Netorials)

    NSDL National Science Digital Library

    Acids and Bases: this is a resource in the collection "Netorials". In this module there is an introduction to the chemical properties of acids and bases. Afterwards, the sections include topics such as Molecular Structures of Acids and Bases, Ionization constants, properties of salts, buffers and Lewis theory of Acids and Bases. The Netorials cover selected topics in first-year chemistry including: Chemical Reactions, Stoichiometry, Thermodynamics, Intermolecular Forces, Acids & Bases, Biomolecules, and Electrochemistry.

  12. Cyclic fatty acids from linolenic acid

    Microsoft Academic Search

    R. A. Eisenhauer; R. E. Beal; E. L. Griffin

    1964-01-01

    Linolenic acid of 95% purity was heated with excess alkali in ethylene glycol to produce cyclic fatty acids. Reaction variables,\\u000a which are associated with the cyclization reaction and which were investigated, included solvent-to-fatty-acid ratio, catalyst\\u000a concentration, and reaction temperature, headspace gas (N2 or C2H4), and head-space gas pressure.\\u000a \\u000a Yields of cyclic acids were improved by increasing solvent ratio (1.5–6 wt

  13. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  14. Lactic acid test

    MedlinePLUS

    Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...

  15. Plasma amino acids

    MedlinePLUS

    Plasma amino acids is a screening test done on infants that looks at the amounts of amino ... Laboratory error High or low amounts of individual plasma amino acids must be considered with other information. ...

  16. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris (Portola Valley, CA); Broun, Pierre (Burlingame, CA); van de Loo, Frank (Lexington, KY)

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  17. Dendritic Cells Hyaluronic Acid

    E-print Network

    Schüler, Axel

    Keywords Dendritic Cells Hyaluronic Acid CD44 Human CD90 Melanoma » Prof. Dr. Jan C. Simon the role of HYALURONIC ACID (HA) and small fragments of HA during DC activation and the participating receptors on DC. (ii) Investigation of the extracellular glucosaminoglycan HYALURONIC ACID, its metabolism

  18. Neutralizing Acids and Bases

    NSDL National Science Digital Library

    2012-04-08

    Learners use their knowledge of color changes with red cabbage indicator to neutralize an acidic solution with a base and then neutralize a basic solution with an acid. Use this as a follow-up activity to the related activity, "Color Changes with Acids and Bases."

  19. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  20. Anaerobic Amino Acid Metabolism

    Microsoft Academic Search

    R. Reggiani; A. Bertani

    2003-01-01

    Anoxic stress induces a strong change in sugar, protein, and amino acid metabolism in higher plants. Sugars are rapidly consumed through the anaerobic glycolysis to sustain energy production. Protein degradation under anoxia is a mechanism to release free amino acids contributing in this way to maintaining the osmotic potential of the tissue under stress. Among free amino acids, a particular

  1. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  2. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  3. Nucleic acid detection assays

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  4. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Waunakee, WI); Lyamichev, Victor I. (Madison, WI); Brow; Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  5. Nucleic acid detection compositions

    SciTech Connect

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann (Madison, WI); Dahlberg, James L. (Madison, WI)

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  6. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor L. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  7. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2000-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  8. Editorial: Acid precipitation

    SciTech Connect

    NONE

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  9. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (inventors)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  10. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  11. The linoleic acid and trans fatty acids of margarines1

    Microsoft Academic Search

    J. L. Beare-Rogers; L. M. Gray; R. Hollywood

    Fifty brands of margarine were analysed for cis-polyunsaturated acids by lipox- idase, for trans fatty acid by infrared spectroscopy, and for fatty acid composition by gas-liquid chromatography. High concentrations of trans fatty acids tended to be associated with low concentrations of hinoleic acid. Later analyses on eight of the brands, representing various proportions of linoleic to trans fatty acids, indicated

  12. 78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ...AGENCY 40 CFR Part 180 [EPA-HQ-OPP-2013-0057; FRL-9381-2] Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance Exemption AGENCY: Environmental Protection Agency (EPA). ACTION:...

  13. Demospongic Acids Revisited

    PubMed Central

    Kornprobst, Jean-Michel; Barnathan, Gilles

    2010-01-01

    The well-known fatty acids with a ?5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32) and from some terrestrial plants with short acyl chains (C18–C19). Finally, the ?5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between ?5,9 fatty acids and other NMI FAs. PMID:21116406

  14. Nucleic acid detection kits

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  15. Effects of iron and manganese on the formation of HAAs upon chlorinating Chlorella vulgaris

    Microsoft Academic Search

    Fei Ge; Xiuzhen Wu; Na Wang; Runliang Zhu; Tong Wang; Yin Xu

    2011-01-01

    The major objective of the present study was to investigate the role of iron and manganese on the formation of haloacetic acids (HAAs) when algae are chlorinated at different pHs. The results showed that both iron and manganese can reduce the yields of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) on chlorinating green alga Chlorella vulgaris (C. vulgaris) at a

  16. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  17. Prediction of Effective Acid Penetration and Acid Volume for Matrix Acidizing Treatments in Naturally Fractured Carbonates

    Microsoft Academic Search

    Xiong Hongjie

    1994-01-01

    This paper discusses a new method and a corresponding computer model developed to investigate matrix acidizing in naturally fractured carbonates. With this method, the effective acid penetration distance and acid volume needed for acid treatments in naturally fractured carbonates can be predicted. The new model simulates acid flowing in the natural fracture network and the acid\\/rock reaction. During the simulation,

  18. CHRONIC ADMINISTRATION OF DOCOSAHEXAENOIC ACID OR EICOSAPENTAENOIC ACID, BUT NOT ARACHIDONIC ACID,

    E-print Network

    Wurtman, Richard

    CHRONIC ADMINISTRATION OF DOCOSAHEXAENOIC ACID OR EICOSAPENTAENOIC ACID, BUT NOT ARACHIDONIC ACID circulating precursors: choline; a pyrimidine (e.g. uridine); and a poly- unsaturated fatty acid, with UMP plus the omega-3 fatty acid docosa- hexaenoic acid (given by gavage), produces substantial in

  19. Acid Rain Learning Activities

    NSDL National Science Digital Library

    These suggestions for activities allow students to learn about acid deposition in new and interactive ways, both in and out of the classroom. The suggestions are for individuals and small groups, the class as a whole, or for field trips. Students may contact local experts about acid rain issues, investigate the energy sources used to generate electricity by their local power companies, collect cartoons about acid rain and air pollution, or play the roles of scientists or interested parties involved in investigations of acid rain issues. Field trip ideas include visiting a local museum or science center to see exhibits or resources on acid rain, and visiting a local cemetary to examine the effects of acid rain on the headstones.

  20. Kidney amino acid transport

    Microsoft Academic Search

    François Verrey; Dustin Singer; Tamara Ramadan; Raphael N. Vuille-dit-Bille; Luca Mariotta; Simone M. R. Camargo

    2009-01-01

    Near complete reabsorption of filtered amino acids is a main specialized transport function of the kidney proximal tubule.\\u000a This evolutionary conserved task is carried out by a subset of luminal and basolateral transporters that together form the\\u000a transcellular amino acid transport machinery similar to that of small intestine. A number of other amino acid transporters\\u000a expressed in the basolateral membrane

  1. Bile Acid Metabolism

    Microsoft Academic Search

    John Y. L. Chiang

    \\u000a Bile acids are physiological agents that facilitate biliary secretion of lipids and metabolites, and intestinal absorption\\u000a of fat and nutrients. Bile acids are also signaling molecules that activate nuclear receptors and cell signaling pathways\\u000a to regulate hepatic lipid metabolism and homeostasis. Bile acids are synthesized from cholesterol in the liver, stored in\\u000a the gallbladder, secreted to the intestine and reabsorbed

  2. Acid rain on Bermuda

    Microsoft Academic Search

    Timothy Jickells; Anthony Knap; Thomas Church; James Galloway; John Miller

    1982-01-01

    Increased acidity of precipitation due to combustion of fossil fuels has been well documented for both the eastern USA1 and Canada2. The SO2 and NOxemitted by the burning of coal, natural gas, fuel oil and petrol are oxidized in the atmosphere to sulphuric and nitric acids which subsequently give rise to acid precipitation1. However, the SO2 and NOx emitted, and

  3. Lactic Acid Bacteria

    NSDL National Science Digital Library

    This on-line exercise is focused on lactic acid bacteria, a group of related bacteria that produce lactic acid as a result of carbohydrate fermentation. It includes a protocol for the enrichment of lactic acid bacteria from enriched samples (like yogurt, sauerkraut, decaying plant matter, and tooth plaque). Three parameters are measured: growth, culture diversity, and pH. The exercise also includes instructions for the isolation of some of these bacteria by using the streak-plate method.

  4. Molecular Structure of Fumaric acid

    NSDL National Science Digital Library

    2004-11-05

    Fumaric acid is odorless and colorless or white crystalline powder with a fruit acid taste. Fumaric acid is used as a substitute of tartaric acid in beverages and baking powders and as a replacement for citric acid in fruits drinks. It is also used as antioxidant to prevent rancidity in butter, cheese, powdered milk, and other foodstuff. In addition, fumaric acid is a chemical intermediate in the manufacture of pharmaceuticals, synthetic resins and plastics. Fumaric acid can be prepared by catalytic oxidation of benzene or by bacterial action on glucose and it is involved in the production of energy from food. Fumaric acid (known as trans-butanedioic acid) is the trans isomer of maleic acid (also called cis-butanedioic acid). Fumaric acid is more stable than maleic acid and can be prepared by heating maleic acid.

  5. Recovery of organic acids

    DOEpatents

    Verser, Dan W. (Golden, CO); Eggeman, Timothy J. (Lakewood, CO)

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  6. Recovery of organic acids

    SciTech Connect

    Verser, Dan W. (Menlo Park, CA); Eggeman, Timothy J. (Lakewood, CO)

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  7. Idiopathic bile acid catharsis.

    PubMed Central

    Thaysen, E H; Pedersen, L

    1976-01-01

    In the course of extensive routine screening for bile acid malabsorption a few patients were detected in whom chronic diarrhoea was apparently induced by excess bile acid loss which was neither associated with demonstrable conventional ileopathy nor with any other disorder allied to diarrhoea. In three patients subjected to scrutiny the results obtained were in harmony with a concept of idiopathic bile acid catharsis. Ingestion of cholestyramine was followed by immediate relief, but the diarrhoea recurred whenever this treatment was withdrawn. It it suggested that idiopathic bile acid catharsis should be suspected in patients with unexplained chronic diarrhoea and especially in those with a diagnosis of irritable colon with diarrhoea. PMID:1017717

  8. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  9. Acid Rain Students' Site

    NSDL National Science Digital Library

    The EPA developed this colorful website to teach students all about acid rain. First, through clear descriptions and helpful figures users can learn the characteristics of acid rain, its dangers, and how to control it. The website offers an interactive connect-the-dots, word searches, crossword puzzles, and other games. A short movie provides an overview of how the use of coal contributes to acid rain and acid rain's impacts on ecosystems and human health. The website also offers an introduction to the pH scale and tools to measure the pH.

  10. Silicic acid: boric acid complexes as wood preservatives

    Microsoft Academic Search

    Haruhiko Yamaguchi

    2003-01-01

    Wood was treated with a low molecular-weight silicic acid: boric acid agent and examined for increased resistance to termites and combustion. Wood treated with silicic acid only exhibited increased termite resistance, but not to the marked extent observed after treatment with a mixture of silicic and boric acids. Increasing the quantity of boric acid also increased the termite mortality rate

  11. The completely sequenced plasmid pEST4011 contains a novel IncP1 backbone and a catabolic transposon harboring tfd genes for 2,4-dichlorophenoxyacetic acid degradation.

    PubMed

    Vedler, Eve; Vahter, Merle; Heinaru, Ain

    2004-11-01

    The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterium Achromobacter xylosoxidans subsp. denitrificans strain EST4002 contains plasmid pEST4011. This plasmid ensures its host a stable 2,4-D(+) phenotype. We determined the complete 76,958-bp nucleotide sequence of pEST4011. This plasmid is a deletion and duplication derivative of pD2M4, the 95-kb highly unstable laboratory ancestor of pEST4011, and was self-generated during different laboratory manipulations performed to increase the stability of the 2,4-D(+) phenotype of the original strain, strain D2M4(pD2M4). The 47,935-bp catabolic region of pEST4011 forms a transposon-like structure with identical copies of the hybrid insertion element IS1071::IS1471 at the two ends. The catabolic regions of pEST4011 and pJP4, the best-studied 2,4-D-degradative plasmid, both contain homologous, tfd-like genes for complete 2,4-D degradation, but they have little sequence similarity other than that. The backbone genes of pEST4011 are most similar to the corresponding genes of broad-host-range self-transmissible IncP1 plasmids. The backbones of the other three IncP1 catabolic plasmids that have been sequenced (the 2,4-D-degradative plasmid pJP4, the haloacetate-catabolic plasmid pUO1, and the atrazine-catabolic plasmid pADP-1) are nearly identical to the backbone of R751, the archetype plasmid of the IncP1 beta subgroup. We show that despite the overall similarity in plasmid organization, the pEST4011 backbone is sufficiently different (51 to 86% amino acid sequence identity between individual backbone genes) from the backbones of members of the three IncP1 subgroups (the alpha, beta, and gamma subgroups) that it belongs to a new IncP1subgroup, the delta subgroup. This conclusion was also supported by a phylogenetic analysis of the trfA2, korA, and traG gene products of different IncP1 plasmids. PMID:15489427

  12. EXPOSURES TO ACIDIC AEROSOLS

    EPA Science Inventory

    Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...

  13. Proteins and Amino Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the most abundant substances in living organisms and cells. All proteins are constructed from the same twenty amino acids that are linked together by covalent bonds. Shorter chains of two or more amino acids can be linked by covalent bonds to form polypeptides. There are twenty amino...

  14. Tautomerism of Penicillic Acid

    Microsoft Academic Search

    C. W. Munday

    1949-01-01

    THE existence of tautomeric forms of penicillic acid was first postulated by Birkinshaw, Oxford arid Raistrick1. Recent workers have tended to the view that the hypothesis of tautomerism was not needed to explain the chemical properties of penicillic acid2.

  15. Salicylic Acid Topical

    MedlinePLUS

    Propa pH® Peel-Off Acne Mask ... pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat ... medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked ...

  16. Strong Acids (GCMP)

    NSDL National Science Digital Library

    Strong Acids: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore the properties of common strong acids. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

  17. Acids and Salts (GCMP)

    NSDL National Science Digital Library

    Acids and Salts: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore a few properties of common acids and their salts. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

  18. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  19. Controlling acid rain

    E-print Network

    Fay, James A.

    1983-01-01

    High concentrations of sulfuric and nitric acid in raTn fn the northeastern USA are caused by the large scale combustion of fossil fuels within this region. Average precipitation acidity is pH 4.2, but spatial and temporal ...

  20. What Causes Acid Rain?

    NSDL National Science Digital Library

    The phenomenon is the formation of acid rain. The resource explains the chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air, mix and react with water and other chemicals to form more acidic pollutants that dissolve very easily in water and can be carried long distances where they become part of rain, sleet, snow, and fog.

  1. EFFECTS OF ACID PRECIPITATION

    EPA Science Inventory

    Recent reviews of available data indicate that precipitation in a large region of North America is highly acidic when its pH is compared with the expected pH value of 5.65 for pure rain water in equilibrium with CO2. A growing body of evidence suggests that acid rain is responsib...

  2. Characterization of acid tars.

    PubMed

    Leonard, Sunday A; Stegemann, Julia A; Roy, Amitava

    2010-03-15

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain. PMID:19857924

  3. Acid in water

    NSDL National Science Digital Library

    Laszlo Ilyes (None; )

    2007-05-16

    Plants and animals that live in water create some amount of acid in the water. The carbon dioxide that plants and animals release into the water makes the water acidic and unsafe for living organisms. This is why the water of captive aquatic animals and plants must be changed often.

  4. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  5. Acid Rain Revisited

    NSDL National Science Digital Library

    Sanders, Hilary C.

    2001-01-01

    The results of a long term study of the effects of acidic deposition in the Northeast were published in Bioscience this week, and they suggest that forests, lakes, and streams of the Northeastern US are not recovering from the toxic effects of acid rain despite significant cuts in the power plant emissions of sulfur dioxide and nitrogen oxide -- two major contributors to the problem. "Acid rain," more accurately called acidic deposition, causes toxic forms of aluminum to concentrate in soil and water, vital calcium and magnesium to be leached from trees, and surface waters to become inhospitable to aquatic biota. The study showed that, after 30 years of federally mandated air emission reductions, sulfur dioxide emissions have decreased while nitrogen oxide emissions have remained the same and that acidic deposition-related problems continue to plague New York and New England.

  6. Sialic Acid Utilization123

    PubMed Central

    Sprenger, Norbert; Duncan, Peter I.

    2012-01-01

    Early postnatal development encounters milk as a key environmental variable and yet the sole nutrient source. One evolutionary conserved constituent of milk is sialic acid, which is generally displayed on glycoconjugates and free glycans. During early postnatal development, high sialic acid need was proposed to be unmet by the endogenous sialic acid synthetic capacity. Hence, milk sialic acid was proposed to serve as a conditional nutrient for the newborn. In the elderly, at the other end of ontogeny, decreased sialylation in the brain, saliva, and immune system is observed. Analogous to the neonatal situation, the endogenous synthetic capacity may be unable to keep up with the need in this age group. The data discussed here propose a functional dietary role of sialic acid as a building block for sialylation and beyond. PMID:22585917

  7. Carboxylic Acid Unknowns and Titration 90 CARBOXYLIC ACID UNKNOWN

    E-print Network

    Jasperse, Craig P.

    Carboxylic Acid Unknowns and Titration 90 CARBOXYLIC ACID UNKNOWN A. Solubility Tests: Water, Na the formula weight. #12;Carboxylic Acid Unknowns and Titration 91 Note: Do your titration once, and check

  8. Reprints of EPA methods for chemical analyses under the information collection rule

    SciTech Connect

    NONE

    1996-04-01

    ;Table of Contents: Determination of Inorganic Anions by Ion Chromatography; Determination of Ammonia Nitrogen By Semi-Automated Colorimetry; Determination of Chlorination Disinfection Byproducts, Chlorinated Solvents, and Halogenated Pesticides/Herbicides in Drinking Water by Liquid-Liquid Extraction and Gas Chromatography with Electron-Capture Detection; Determination of Haloacetic Acids and Dalapon in Drinking Water by Ion-Exchange Liquid-Solid Extraction and Gas-Chromatography with an Electron Capture Detector; and Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Extraction, Derivatization and Gas Chromatography with Electron Capture Detection.

  9. CLA production from ricinoleic acid by lactic acid bacteria

    Microsoft Academic Search

    Akinori Ando; Jun Ogawa; Shigenobu Kishino; Sakayu Shimizu

    2003-01-01

    The ability to produce CLA from ricinoleic acid is widely distributed in lactic acid bacteria. Washed cells of Lactobacillus plantarum JCM 1551 were selected as a potential catalyst for CLA production from ricinoleic acid. Cells cultivated in medium supplemented\\u000a with a mixture of ?-linolenic acid and linoleic acid showed enhanced CLA productivity. Under optimal reaction conditions,\\u000a with the free acid

  10. Antioxidant activity of caffeic acid (3,4-dihydroxycinnamic acid)

    Microsoft Academic Search

    ?lhami Gülçin

    2006-01-01

    Caffeic acid (3,4-dihydroxycinnamic acid) is among the major hydroxycinnamic acids present in wine; sinapic acid, which is a potent antioxidant. It has also been identified as one of the active antioxidant. In the present study, the antioxidant properties of the caffeic acid were evaluated by using different in vitro antioxidant assays such as 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free

  11. ORGANOSULPHUR PHOSPHORUS ACID COMPOUNDS. PART 4. FLUOROBENZYLPHOSPHONO-SULPHONIC ACIDS

    Microsoft Academic Search

    E. Montoneri; P. Savarino; G. Viscardi; M. C. Gallazzi

    1994-01-01

    Four new organosulphur phosphorus acid compounds have been obtained by sulphonation with liquid SO3: 2-fluorobenzylphosphonic and 4-fluorobenzylphosphonic acids gave 2-fluorobenzylphosphono-5-sulphonic and 4-fluorobenzylphosphono-3-sulphonic acids respectively, in nearly quantitative yields; 3-fluorobenzylphosphonic acid gave 3-fluorobenzylphosphono-6-sulphonic acid (85%) and 3-fluorobenzylphosphono-4-sulphonic acid (15%). Product structures are based on C magnetic resonance data. The entry of the SO3H group into the aromatic ring seems mainly ruled

  12. EXPOSURE TO A P13KINASE INHIBITOR PRODUCED DYSMORPHOGENESIS IN NEURULATION-STAGED MOUSE EMBRYOS IN CULTURE

    EPA Science Inventory

    The haloacetic acids (HAA) are a family of chemicals that are drinking water disinfection byproducts. We previously reported that bromo- and chloro-acetic acids alter embryonic development when mouse conceptuses are directly exposed to these xenobiotics in whole embryo culture. C...

  13. WASTE ACID DETOXIFICATION AND RECLAMATION

    EPA Science Inventory

    This Environmental Security Technology Certification Program (ESTCP) project demonstrated the Waste Acid Detoxification and Reclamation (WADR) systems ability to recover waste electropolish acid solutions generated during the manufacturing of gun-tubes, and reuse the clean acid. ...

  14. Gluconic acid production.

    PubMed

    Anastassiadis, Savas; Morgunov, Igor G

    2007-01-01

    Gluconic acid, the oxidation product of glucose, is a mild neither caustic nor corrosive, non toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries. Present review article presents the comprehensive information of patent bibliography for the production of gluconic acid and compares the advantages and disadvantages of known processes. Numerous manufacturing processes are described in the international bibliography and patent literature of the last 100 years for the production of gluconic acid from glucose, including chemical and electrochemical catalysis, enzymatic biocatalysis by free or immobilized enzymes in specialized enzyme bioreactors as well as discontinuous and continuous fermentation processes using free growing or immobilized cells of various microorganisms, including bacteria, yeast-like fungi and fungi. Alternatively, new superior fermentation processes have been developed and extensively described for the continuous and discontinuous production of gluconic acid by isolated strains of yeast-like mold Aureobasidium pullulans, offering numerous advantages over the traditional discontinuous fungi processes. PMID:19075839

  15. Trans Fatty Acids

    NASA Astrophysics Data System (ADS)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  16. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  17. Molecular Structure of Gallic acid

    NSDL National Science Digital Library

    2003-05-08

    Gallic acid is found in its free state and combined with the tannin molecule, from which it can be extracted by the hydrolysis of tannic acid with sulfuric acid. Since one molecule of gallic acid has a carboxylic acid group and hydroxyl groups, it can react with another molecule of gallic acid to form an ester, digallic acid. When heated above 200 degrees C, gallic acid loses carbon dioxide to form pyrogallol (1,2,3-trihydroxybenzene, C6H3(OH)3), which is used in the production of azo dyes, photographic developers, and in laboratories for absorbing oxygen.

  18. Aminolevulinic Acid Topical

    MedlinePLUS

    ... in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty or scaly ... photosensitizing agents. When aminolevulinic acid is activated by light, it damages the cells of actinic keratosis lesions.

  19. Acid-Base Tutorial

    NSDL National Science Digital Library

    MD Alan W. Grogono (Tulane University School of Medicine Dept. of Anesthesiology)

    2002-06-01

    Website for anyone wanting to become more familiar with the physiology of acid-base balance in clinical medicine. Several pages are interactive. Numerical results are accompanied by text interpretations to facilitate recognition and understanding.

  20. Fatty Acid Carcass Mapping 

    E-print Network

    Turk, Stacey N.

    2010-01-14

    We hypothesized that subcutaneous (s.c.) adipose tissue would differ in monounsaturated (MUFA) and saturated fatty acid (SFA) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types...

  1. Stomach acid test

    MedlinePLUS

    Gastric acid secretion test ... The test is done after a period of not eating so that fluid is all that remains in the ... the stomach through the esophagus (food pipe). To test the ability of the cells in the stomach ...

  2. Amoxicillin and Clavulanic Acid

    MedlinePLUS

    ... is used to treat certain infections caused by bacteria, including infections of the ears, lungs, sinus, skin, ... antibiotics. It works by stopping the growth of bacteria. Clavulanic acid is in a class of medications ...

  3. ACID RAIN CONTROL OPTIONS

    EPA Science Inventory

    The paper discusses acid rain control options available to the electric utility industry. They include coal switching, flue gas desulfurization, and such emerging lower cost technologies as Limestone Injection Multistage Burners (LIMB) and Advanced Silicate (ADVACATE) both develo...

  4. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  5. Folic acid (image)

    MedlinePLUS

    ... show that an increase in the mother's dietary folic acid before conception and during the first month of pregnancy reduces the risk of having a child with a neural tube defect. The recommendation is that women of childbearing years ...

  6. Diversity of Oleic Acid, Ricinoleic Acid and Linoleic Acid Conversions Among Pseudomonas aeruginosa Strains

    Microsoft Academic Search

    Tsung Min Kuo; Lawrence K. Nakamura

    2004-01-01

    Sixteen Pseudomonas aeruginosa strains, including patent strain NRRL B-18602, three recent isolates from composted materials amended with ricinoleic acid, and 12 randomly selected from the holdings of the ARS Culture Collection, were examined for their fatty acid converting abilities. The study examined the bioconversion of oleic acid to 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) and ricinoleic acid to 7,10,12-trihydroxy-8(E)-octadecenoic acid (TOD). A new

  7. Folic Acid Recommendations Survey

    Microsoft Academic Search

    S. A. Pinkham; K. Cobb

    1999-01-01

    This study was designed to determine the current practices of women's health care providers with regard to folic acid knowledge and recommendations. Two-hundred-twenty obstetrician\\/gynecologists and certified nurse-midwives participated by completing questionnaires.A gap between the belief that folic acid reduces the risk of neural tube defects [NTDs] and the lack of widespread supplementation recommendations was revealed. Results showed that only 45%

  8. Acid-base chemistry

    SciTech Connect

    Hand, C.W.; Blewit, H.L.

    1985-01-01

    The book is not a research compendium and there are no references to the literature. It is a teaching text covering the entire range of undergraduate subject matter dealing with acid-base chemistry (some of it remotely) as taught in inorganic, analytical, and organic chemistry courses. The excellent chapters VII through IX deal in detail with the quantitative aspects of aqueous acid-base equilibria (salt hydrolysis and buffer, titrations, polyprotic and amphoteric substances).

  9. Acid Rain Lesson Plan

    NSDL National Science Digital Library

    Five articulated lessons focus on air quality using classroom and field data collection activities. Case study in Great Smoky Mountains has broader application. Background and data for lessons on: the pH scale, understanding acid vs. base, collecting data, mapping relationship of weather events to acid rain. Links to NPS data on air quality, current values, atlas and reports, packaged datasets on ozone, meteorological conditions and other parameters. Also available: teacher resources; educator workshops.

  10. Biodegradation of polyhydroxyalkanoic acids

    Microsoft Academic Search

    D. Jendrossek; A. Schirmer; H. G. Schlegel

    1996-01-01

    Stimulated by the commercial availability of bacteriologically produced polyesters such as poly[(R)-3-hydroxybutyric acid], and encouraged by the discovery of new constituents of polyhydroxyalkanoic acids (PHA), a considerable\\u000a body of knowledge on the metabolism of PHA in microorganisms has accumulated. The objective of this essay is to give an overview\\u000a on the biodegradation of PHA. The following topics are discussed: (i)

  11. Thin-layer chromatography of gallic acid, methyl gallate, pyrogallol, phloroglucinol, catechol, resorcinol, hydroquinone, catechin, epicatechin, cinnamic acid, p-coumaric acid, ferulic acid and tannic acid

    Microsoft Academic Search

    Om Prakash Sharma; Tej Krishan Bhat; Bhupinder Singh

    1998-01-01

    Six solvent systems of varying suitability are reported for the thin-layer chromatographic separation of simple phenolics and related compounds such as gallic acid, methyl gallate, pyrogallol, phloroglucinol, catechol, resorcinol, hydroquinone, catechin, epicatechin, cinnamic acid, p-coumaric acid, ferulic acid and tannic acid. The solvent system chloroform-ethyl acetate-acetic acid (50:50:1) facilitated the separation of all the compounds except pyrogallol and ferulic acid;

  12. Managing bile acid diarrhoea

    PubMed Central

    Walters, Julian R. F.; Pattni, Sanjeev S.

    2010-01-01

    Bowel symptoms including diarrhoea can be produced when excess bile acids (BA) are present in the colon. This condition, known as bile acid or bile salt malabsorption, has been under recognized, as the best diagnostic method, the 75Se-homocholic acid taurine (SeHCAT) test, is not available in many countries and is not fully utilized in others. Reduced SeHCAT retention establishes that this is a complication of many other gastrointestinal diseases. Repeated studies show SeHCAT tests are abnormal in about 30% of patients otherwise diagnosed as diarrhoea-predominant irritable bowel syndrome or functional diarrhoea, with an estimated population prevalence of around 1%. Recent work suggests that the condition previously called idiopathic bile acid malabsorption (BAM) is not in fact due to a defect in absorption, but results from an overproduction of BA because of defective feedback inhibition of hepatic bile acid synthesis, a function of the ileal hormone fibroblast growth factor 19 (FGF19). The approach to treatment currently depends on binding excess BA, to reduce their secretory actions, using colestyramine, colestipol and, most recently, colesevelam. Colesevelam has a number of potential advantages that merit further investigation in trials directed at patients with bile acid diarrhoea. PMID:21180614

  13. Portable nucleic acid thermocyclers.

    PubMed

    Almassian, David R; Cockrell, Lisa M; Nelson, William M

    2013-11-21

    A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies. PMID:24030680

  14. Original article Acid stress susceptibility and acid adaptation

    E-print Network

    Paris-Sud XI, Université de

    Original article Acid stress susceptibility and acid adaptation of Propionibacterium freudenreichii as their use in cheese tech- nology implies exposure to various environmental stresses, including acidic pH. The acid tolerance response (ATR) of Propionibacterium freudenreichii was investigated. One strain present

  15. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  16. What is Acid Rain? Explore the Acid Lake

    NSDL National Science Digital Library

    Earth Day Canada

    2010-01-01

    Acid rain is a type of air pollution that occurs when certain chemicals mix with water in the air. Most chemicals that cause acid rain come from the emissions from factories and cars. Acid rain looks just like 'normal' rain but when it falls, it can hurt plants and animals. For example, when acid rain falls into a lake or river, it makes that body of water more acidic. Many plants and animals cannot live in acidic water. Play this game, from Earth Day Canada's EcoKids program, to learn more about acid rain and its impact on the environment.

  17. Antimicrobial activity of some ricinoleic acid oleic acid derivatives

    Microsoft Academic Search

    Arthur F. Novak; Gladys C. Clark; Harold P. Dupuy

    1961-01-01

    Ricinoleic and acid oleic acid derivatives were screened for their antimicrobial activity, under optimum growing-conditions,\\u000a against several species of bacteria, yeasts, and molds. Several ricinoleic acid derivatives and petroselinic (iso-oleic) acid\\u000a exhibited considerable activity; in fact, their activity against some micro-organisms was comparable to sorbic and 10-undecenoic\\u000a acid, known antimicrobial agents, as indicated by this test.

  18. Composition for nucleic acid sequencing

    Microsoft Academic Search

    Jonas Korlach; Watt W. Webb; Michael Levene; Stephen Turner; Harold G. Craighead; Mathieu Foquet

    2008-01-01

    The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is

  19. Ursodeoxycholic acid, 7-ketolithocholic acid, and chenodeoxycholic acid are primary bile acids of the nutria (Myocastor coypus).

    PubMed

    Tint, G S; Bullock, J; Batta, A K; Shefer, S; Salen, G

    1986-03-01

    Because ursodeoxycholic and chenodeoxycholic acids are interconverted in humans via 7-ketolithocholic acid, bile acid metabolism was studied in the nutria (Myocastor coypus), the bile of which is known to contain these three bile acids. Relative concentrations of ursodeoxycholic (37% +/- 20%), 7-ketolithocholic (33% +/- 17%), and chenodeoxycholic (17% +/- 9%) acids in gallbladder bile were unchanged by 5-20 h of complete biliary diversion (n = 7). Injection of either [14C]cholesterol, [14C]ursodeoxycholic, [14C]7-ketolithocholic acid, or a mixture of [7 beta-3H]chenodeoxycholic acid and [14C]chenodeoxycholic acid into bile fistula nutria demonstrated that all three bile acids can be synthesized hepatically from cholesterol, that they are interconverted sparingly (2%-5%) by the liver, but that 7-ketolithocholic acid is an intermediate in the hepatic transformation of chenodeoxycholic acid to ursodeoxycholic acid. An animal that had been fed antibiotics showed an unusually elevated concentration of ursodeoxycholic acid in gallbladder and hepatic bile, suggesting that bacterial transformation of ursodeoxycholic acid in the intestine may be a source of some biliary chenodeoxycholic acid and 7-ketolithocholic acid. PMID:3943698

  20. Acid Catalysis in Modern Organic

    E-print Network

    Snyder, Scott A.

    Acid Catalysis in Modern Organic Synthesis "Acid is one of the oldest, but the most important follows their earlier book "Lewis Acids in Organic Synthesis (2000)", and covers the new developments of university studies, in which an evil-smelling carbox- ylic acid and an alcohol were converted into a fragrant

  1. Molecular Structure of Malonic acid

    NSDL National Science Digital Library

    2002-10-10

    Propanedioic acid is a dibasic carboxylic acid that was first synthesized by oxidizing malic acid in 1858 by a scientist named Dessaigne. Naturally, propandioic acid is found in apples. This chemical is relatively unstable and has few uses, but its ester derivative, diethyl malonate, is used to synthesize useful compounds such as barbiturates, flavors, fragrances, and vitamins (B1 and B6).

  2. Atmospheric Dust and Acid Rain

    Microsoft Academic Search

    Lars O. Hedin; Gene E. Likens

    1996-01-01

    Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid

  3. Corrosion inhibitors used in acidizing

    SciTech Connect

    Cizek, A. (Baker Performance Chemicals Inc., Houston, TX (United States). Aquaness Chemical Division)

    1994-01-01

    The history of the development of oil well acidizing and acid corrosion inhibitors used by this industry is reviewed. As deeper and hotter wells were drilled, stimulation acids were exposed to hotter conditions and the organic inhibitors required intensifiers. High-temperature acid corrosion inhibitors are also discussed.

  4. Triterpenic acids in table olives

    Microsoft Academic Search

    Concepción Romero; Aranzazu García; Eduardo Medina; Antonio de Castro; Manuel Brenes

    2010-01-01

    An experimental investigation was carried out for the first time on the triterpenic acids in table olives. Maslinic acid was found in a higher concentration than oleanolic acid in the flesh of 17, unprocessed olive varieties, with the Picual and the Manzanilla varieties showing the highest and almost the lowest contents, respectively. The level of triterpenic acids in several types

  5. Pelargonic acid weed control parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers and researchers are interested in pelargonic acid (nonanoic acid) as a broad-spectrum post-emergence or burn-down herbicide. Pelargonic acid is a fatty acid naturally occurring in many plants and animals, and present in many foods we consume. The objective of this research was to determine...

  6. Molecular Structure of Succinic acid

    NSDL National Science Digital Library

    2004-11-11

    Succinic acid is an odorless and colorless crystal, triclinic or monoclinic prism with a very acid taste. Succinic acid is one of the natural acids found in broccoli, rhubarb, beets, asparagus, fresh meat extracts, sauerkraut and cheese. It is also a constituent of almost all plant and animal tissues and plays an important role in intermediary metabolism. Succinic acid is produced commercially by catalytic hydrogenation of maleic or fumaric acid or by acid hydrolysis of succinonitrile. Succinic acid is used in flavoring for food and beverages, and in the manufacture of lacquers, dyes, esters for perfumes, succinates, in photography and in foods as a sequestrant, buffer and neutralizing agent. Succinic acid has uses in certain drug compounds and in agricultural production. An interesting fact, succcinic acid has also been found in meteorites.

  7. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  8. Asphaltene damage in matrix acidizing 

    E-print Network

    Hinojosa, Roberto Antonio

    1996-01-01

    REVIEW CONSTRUCTION OF APPARATUS . DESCRIPTION OF CORE SAMPLES DESIGN OF EXPERIMENTAL ACID TREATMENT . . . ACIDIZING RESULTS BRINE SATURATED CORE L1D ACIDIZING RESULTS BRINE/CRUDE OIL SATURATED CORE S2A . . . ACIDIZING RESULTS BRINE/KEROSENE OIL... experiment they used HCl saturated kerosene to test the same crude samples. Deposition occurred with the HCl saturated acid. The authors concluded, though deposition at an interface was preferential, sludge formation did not require an interface. Moore et...

  9. Molecular Structure of Citric Acid

    NSDL National Science Digital Library

    2002-08-13

    Citric Acid was first isolated in 1734 by Carl Wilhelm Scheele. Citric acid is found in many fruits, in particular lemons, grapefruit, and oranges. Several types of bacteria and fungi are also known to produce citric acid. In fact, the fungus Aspergillus niger produces the vast majority of citric acid, which is used in almost all carbonated sodas. Additionally, citric acid is also used to clean stainless steel.

  10. Science Shorts: Understanding Acid Rain

    NSDL National Science Digital Library

    Kathleen Damonte

    2004-11-01

    You may have heard acid rain mentioned as an environmental problem. It doesn't mean that a strong chemical is raining from the sky. The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. However, a small change in how acidic precipitation is can have a profound effect. This month's activity will help students understand the effect of acid rain on buildings and statues.

  11. Optical high acidity sensor

    DOEpatents

    Jorgensen, Betty S. (Jemez Springs, NM); Nekimken, Howard L. (Los Alamos, NM); Carey, W. Patrick (Lynnwood, WA); O'Rourke, Patrick E. (Martinez, GA)

    1997-01-01

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and, a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber.

  12. Acid neutralizing capacity, alkalinity, and acid-base status of natural waters containing organic acids

    Microsoft Academic Search

    Harold F. Hemond

    1990-01-01

    The terms acid neutralizing capacity (ANC) and alkalinity (Alk) are extensively employed in the characterization of natural waters, including soft circumneutral or acidic waters. However, in the presence of organic acids, ANC measurements are inconsistent with many conceptual definitions of ANC or Alk and do not provide an adequate characterization of the acid-base chemistry of water. Knowledge of Gran ANC

  13. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  14. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 ...acid amine condensate, polycarboxylic acid salts. (a) Chemical substance and significant...acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject...

  15. Thiol modified mycolic acids.

    PubMed

    Balogun, Mohammed O; Huws, Enlli H; Sirhan, Muthana M; Saleh, Ahmed D; Al Dulayymi, Juma'a R; Pilcher, Lynne; Verschoor, Jan A; Baird, Mark S

    2013-01-01

    Patient serum antibodies to mycolic acids have the potential to be surrogate markers of active tuberculosis (TB) when they can be distinguished from the ubiquitously present cross-reactive antibodies to cholesterol. Mycolic acids are known to interact more strongly with antibodies present in the serum of patients with active TB than in patients with latent TB or no TB. Examples of single stereoisomers of mycolic acids with chain lengths corresponding to major homologues of those present in Mycobacterium tuberculosis have now been synthesised with a sulfur substituent on the terminal position of the ?-chain; initial studies have established that one of these binds to a gold electrode surface, offering the potential to develop second generation sensors for diagnostic patient antibody detection. PMID:23603063

  16. Bioavailability of ferulic acid.

    PubMed

    Bourne, L C; Rice-Evans, C

    1998-12-18

    There is a wealth of evidence for the powerful antioxidant properties in vitro of flavonoid components of the diet. However, few studies have been undertaken concerning the hydroxycinnamates, major constituents of fruit, some vegetables, beverages, and grains, particularly the extent to which they are absorbed in vivo from the diet. The study described here has investigated the bioavailability of ferulic acid in humans, from tomato consumption, through the monitoring of the pharmacokinetics of excretion in relation to intake. The results show that the peak time for maximal urinary excretion is approximately 7 h and the recovery of ferulic acid in the urine, on the basis of total free ferulic acid and feruloyl glucuronide excreted, is 11-25% of that ingested. PMID:9878519

  17. Oleanolic acid ethanol monosolvate

    PubMed Central

    Froelich, Anna; Gzella, Andrzej K.

    2010-01-01

    Crystals of the title compound (systematic name: 3?-hy­droxy­olean-12-en-28-oic acid ethanol monosolvate), C30H48O3·C2H5OH, were obtained from unsuccessful co-crystallization trials. The asymmetric unit contains two symmetry-independent oleanolic acid mol­ecules, as well as two ethanol solvent mol­ecules. Inter­molecular O—H?O hydrogen bonds stabilize the crystal packing. In the oleanolic acid mol­ecules, ring C has a slightly distorted envelope conformation, while rings A, B, D and E adopt chair conformations and rings D and E are cis-fused. Both independent ethanol mol­ecules are orientationally disordered [occupancy ratios of 0.742?(8):0.258?(8) and 0.632?(12):0.368?(12). PMID:21588987

  18. [Studies on interaction of acid-treated nanotube titanic acid and amino acids].

    PubMed

    Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

    2010-06-01

    Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination. PMID:20649031

  19. Acid rain in Asia

    NASA Astrophysics Data System (ADS)

    Bhatti, Neeloo; Streets, David G.; Foell, Wesley K.

    1992-07-01

    Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world.

  20. Ethylenediaminetetraacetic acid in endodontics

    PubMed Central

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-01-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented. PMID:24966721

  1. Acid Deposition Lab

    NSDL National Science Digital Library

    In this activity students will design an apparatus and carry out tests of fossil fuels to determine their impact on acid deposition by placing a small amount of a fossil fuel on a cotton puff and burning it to measure if acidic compounds are given off. Students will provide a diagram of their collection device and describe how it should function. Students will then draw a map showing the location of their precipitation collector and develop a graph or chart based on the results they have collected.

  2. Lactic acid bacterial cell factories for gamma-aminobutyric acid

    Microsoft Academic Search

    Haixing Li; Yusheng Cao

    2010-01-01

    Gamma-aminobutyric acid is a non-protein amino acid that is widely present in organisms. Several important physiological functions\\u000a of gamma-aminobutyric acid have been characterized, such as neurotransmission, induction of hypotension, diuretic effects,\\u000a and tranquilizer effects. Many microorganisms can produce gamma-aminobutyric acid including bacteria, fungi and yeasts. Among\\u000a them, gamma-aminobutyric acid-producing lactic acid bacteria have been a focus of research in recent

  3. Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    DOEpatents

    Moens, Luc (Lakewood, CO)

    2003-06-24

    A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.

  4. Molecular Structure of Aspartic Acid

    NSDL National Science Digital Library

    2002-08-20

    Aspartate was first isolated in 1868 from legumin in plant seeds. Aspartic acid forms colorless crystals that are soluble in water and insoluble in alcohols and ethers. This is a naturally occurring nonessential amino acid that is produced in the liver from oxaloacetic acid, but is plentiful in meats and sprouting seeds. The amino acid is important in the Krebs cycle as well as the urea cycle, where it is vital in the elimination of dietary waste products. Aspartic acid is required for stamina, brain and neural health. This acid has been found to be important in the functioning of ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and in the production of immunoglobin and antibody synthesis. A deficiency of aspartate will lead to fatigue and depression. Aspartic acid has many uses that include biological and clinical studies, preparation of culture media, and it also functions as a detergent, fungicide, germicide, and metal complexation.

  5. Cysteic Acid Transaminase

    Microsoft Academic Search

    Sven Darling

    1952-01-01

    IT has previously been reported by Cohen1 that enzyme preparations catalysing the reactions : (1) Alanine + alpha-ketoglutarate rlharr glutamate + pyruvate; (2) Aspartate + alpha-ketoglutarate rlharr glutamate + oxalo acetate; are also capable of catalysing : (3) Cysteic acid + alpha-ketoglutarate rlharr glutamate + sulphopyruvate. (In a succeeding paper it will be shown that reaction (3) is reversible, which

  6. Microbial hyaluronic acid production

    Microsoft Academic Search

    Barrie Fong Chong; Lars M. Blank; Richard Mclaughlin; Lars K. Nielsen

    2005-01-01

    sHyaluronic acid (HA) is a commercially valuable medical biopolymer increasingly produced through microbial fermentation. Viscosity limits product yield and the focus of research and development has been on improving the key quality parameters, purity and molecular weight. Traditional strain and process optimisation has yielded significant improvements, but appears to have reached a limit. Metabolic engineering is providing new opportunities and

  7. Spermatotoxicity of dichloroacetic acid

    EPA Science Inventory

    The testicular toxicity of dichloroacetic acid (DCA), a disinfection byproduct of drinking water, was evaluated in adult male rats given both single and multiple (up to 14 d) oral doses. Delayed spermiation and altered resorption of residual bodies were observed in rats given sin...

  8. Fumaric acid esters

    Microsoft Academic Search

    Martin Rostami Yazdi; Ulrich Mrowietz

    2008-01-01

    Several clinical studies have shown that systemic therapy with fumaric acid esters (FAEs) in patients with moderate to severe psoriasis is effective and has a good long-term safety profile. For therapeutic use, tablets with a defined mixture of FAEs (dimethylfumarate [DMF] and three different salts of monoethylfumarate) are registered in Germany. There is evidence that DMF is the most essential

  9. ACID AEROSOL MEASUREMENT WORKSHOP

    EPA Science Inventory

    This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...

  10. The Acid Rain Game.

    ERIC Educational Resources Information Center

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…

  11. Acid Rain Investigations.

    ERIC Educational Resources Information Center

    Hugo, John C.

    1992-01-01

    Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)

  12. Acid rain bibliography

    SciTech Connect

    Sayers, C.S.

    1983-09-01

    This bibliography identifies 900 citations on various aspects of Acid Rain, covering published bibliographies, books, reports, conference and symposium proceedings, audio visual materials, pamphlets and newsletters. It includes five sections: citations index (complete record of author, title, source, order number); KWIC index; title index; author index; and source index. 900 references.

  13. Federal Acid Rain Games

    Microsoft Academic Search

    Arthur J. Caplan; Emilson C. D. Silva

    1999-01-01

    Federal environmental policy, designed to control acid rain, is shaped after the hierarchy of the system, and is controlled simultaneously by regional and central governments. Each governmental level controls one of two policy instruments: pollution abatement production and pollution tax. In a two-stage game where regional governments are Stackelberg leaders and control pollution taxes, the subgame perfect equilibrium is socially

  14. Effects of Acid Rain

    NSDL National Science Digital Library

    This portal provides links to information on the potential damage caused to the environment by acid rain. An introductory paragraph briefly describes the damage to lakes and streams, building materials, and monuments. Each link access additional information on these topics: surface waters and aquatic animals, forests, automotive coatings, soluble building materials such as marble or limestone, atmospheric haze, and human health effects.

  15. Acid Rain Classroom Projects.

    ERIC Educational Resources Information Center

    Demchik, Michael J.

    2000-01-01

    Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)

  16. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Bybee, Rodger; And Others

    1984-01-01

    Describes an activity which provides opportunities for role-playing as industrialists, ecologists, and government officials. The activity involves forming an international commission on acid rain, taking testimony, and, based on the testimony, making recommendations to governments on specific ways to solve the problem. Includes suggestions for…

  17. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Oates-Bockenstedt, Catherine

    1997-01-01

    Details an activity designed to motivate students by incorporating science-related issues into a classroom debate. Includes "The Acid Rain Bill" and "Position Guides" for student roles as committee members, consumers, governors, industry owners, tourism professionals, senators, and debate directors. (DKM)

  18. Acidification and Acid Rain

    Microsoft Academic Search

    S. A. Norton

    2003-01-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw

  19. Acid Mine Drainage Remediation

    NSDL National Science Digital Library

    2010-12-10

    In this video, an environmental technologist visits an abandoned coal mine in Kentucky to talk about how a remediation system (a series of settling ponds and treatment cells) is neutralizing the acid drainage flowing from the mine and keeping it from damaging a creek downstream.

  20. Acid Rain: Science Projects.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.

    1989-01-01

    Presented is a science activity designed to help students monitor the pH of rainfall. Materials, procedures and follow-up activities are listed. A list of domestic and foreign sources of information is provided. Topics which relate to acid precipitation are outlined. (CW)

  1. Fatty acid-producing hosts

    DOEpatents

    Pfleger, Brian F; Lennen, Rebecca M

    2013-12-31

    Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.

  2. Inhibition of oxidative degradation of hyaluronic acid by uric acid.

    PubMed

    Liu, K M; Swann, D; Lee, P; Lam, K W

    1984-08-01

    It has been postulated that glycosaminoglycans in the trabeculum have an influence on aqueous humor drainage. Ascorbate reduces the viscosity of hyaluronic acid, and also increases outflow facility. Our recent observation of high urate concentrations in some glaucomatous eyes led us to study the influence of urate on oxidative degradation of hyaluronic acid by ascorbate. The viscosity of rooster comb hyaluronic acid was reduced slowly by ascorbate. Cupric sulfate accelerated ascorbate oxidation and also enhanced hyaluronic acid degradation. Urate inhibited ascorbate oxidation and prevented the copper catalyzed oxidative degradation of rooster comb hyaluronic acid. The range of urate concentrations used in this study was within the range of urate concentrations observed in glaucomatous eyes. The partially purified umbilical cord hyaluronic acid had lower viscosity than rooster comb hyaluronic acid, and rapidly degraded in the presence of ascorbate. The ascorbate effect on umbilical cord hyaluronic acid was partially prevented by urate. PMID:6488856

  3. Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations.

    PubMed

    Ahmad, I; Ali Sheraz, M; Ahmed, S; Shad, Z; Vaid, F H M

    2012-06-01

    This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations. PMID:22296174

  4. Recovery of Carboxylic Acids from Fermentation Broth via Acid Springing

    E-print Network

    Dong, Jipeng

    2010-01-14

    RECOVERY OF CARBOXYLIC ACIDS FROM FERMENTATION BROTH VIA ACID SPRINGING A Thesis by JIPENG DONG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 2008 Major Subject: Chemical Engineering RECOVERY OF CARBOXYLIC ACIDS FROM FERMENTATION BROTH VIA ACID SPRINGING A Thesis by JIPENG DONG Submitted to the Office of Graduate Studies of Texas A...

  5. Fatty acid selectivity of lipases: Erucic acid from rapeseed oil

    Microsoft Academic Search

    Philip E. Sonnet; Thomas A. Foglia; Stephen H. Feairheller

    1993-01-01

    The fatty acid selectivity of several commercial lipases was evaluated in the hydrolysis of high-erucic acid rapeseed oil\\u000a (HEARO). The lipase ofPseudomonas cepacia catalyzed virtually complete hydrolysis of the oil (94–97%), while that ofGeotrichum candidum discriminated strongly against erucic acid, especially in esterification. A two-step process is suggested for obtaining a\\u000a highly enriched erucic acid in which theG. candidum lipase

  6. Thiobarbituric Acid Spray Reagent for Deoxy Sugars and Sialic Acids

    Microsoft Academic Search

    Leonard Warren

    1960-01-01

    RECENTLY, new sensitive assays have been reported for deoxy sugars1, 2-keto,3-deoxy sugar acids2-4, and sialic acids5,6. In these assays, the products of periodate oxidation, malonaldehyde from deoxy sugars and beta-formylpyruvic acid from the latter two groups of compounds, are coupled with 2-thiobarbituric acid to produce a bright red chromophore. I wish to report an adaptation of these methods for spraying

  7. Dietary omega-3 fatty acids for women

    Microsoft Academic Search

    Jean-Marie Bourre

    2007-01-01

    This review details the specific needs of women for omega-3 fatty acids, including alpha linoleic acid (ALA) and the very long chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3 fatty acid (dietary or in capsules) ensures that a woman's adipose tissue contains a reserve of these fatty acids for the developing fetus and the breast-fed newborn infant.

  8. Acid placement and coverage in the acid jetting process 

    E-print Network

    Mikhailov, Miroslav I.

    2009-05-15

    Many open-hole acid treatments are being conducted by pumping acid through jetting ports placed at the end of coiled tubing or drill pipe. The filter-cake on the bore-hole is broken by the jet; the acid-soluble material is dissolved, creating...

  9. Acid Placement in Acid Jetting Treatments in Long Horizontal Wells 

    E-print Network

    Sasongko, Hari

    2012-07-16

    In the Middle East, extended reach horizontal wells (on the order of 25,000 feet of horizontal displacement) are commonly acid stimulated by jetting acid out of drill pipe. The acid is jetted onto the face of the openhole wellbore as the drill pipe...

  10. SPECTROFLUOROMETRIC ASSAY FOR HYPOHALITE AND PEROXYACETIC ACID USING KOJIC ACID

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hypochlorite reacted with kojic acid to form an intensely fluorescent product with excitation and emission wavelengths at 395 and 495 nm, respectively. Hypobromite, generated by reaction of hypochlorite or peroxyacetic acid with NaBr, also reacted with kojic acid to generate an identical fluorescen...

  11. College Chemistry Students' Mental Models of Acids and Acid Strength

    ERIC Educational Resources Information Center

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  12. Acid adaptation sensitizes Salmonella typhimurium to hypochlorous acid.

    PubMed Central

    Leyer, G J; Johnson, E A

    1997-01-01

    Acid adaptation of Salmonella typhimurium at a pH of 5.0 to 5.8 for one to two cell doublings resulted in marked sensitization of the pathogen to halogen-based sanitizers including chlorine (hypochlorous acid) and iodine. Acid-adapted S. typhimurium was more resistant to an anionic acid sanitizer than was its nonadapted counterpart. A nonselective plating medium of tryptose phosphate agar plus 1% pyruvate was used throughout the study to help recover chemically stressed cells. Mechanisms of HOCl-mediated inactivation of acid-adapted and nonadapted salmonellae were investigated. Hypochlorous acid oxidized a higher percentage of cell surface sulfhydryl groups in acid-adapted cells than in nonadapted cells, and sulfhydryl oxidation was correlated with cell inactivation. HOCl caused severe metabolic disruptions in acid-adapted and nonadapted S. typhimurium, such as respiratory loss and inability to restore the adenylate energy charge from a nutrient-starved state. Sensitization of S. typhimurium to hypochlorous acid by acid adaptation also involved increased permeability of the cell surface because nonadapted cells treated with EDTA became sensitized. The results of this study establish that acid-adapted S. typhimurium cells are highly sensitized to HOCl oxidation and that inactivation by HOCl involves changes in membrane permeability, inability to maintain or restore energy charge, and probably oxidation of essential cellular components. This study provides a basis for improved practical technologies to inactivate Salmonella and implies that acid pretreatment of food plant environments may increase the efficacy of halogen sanitizers. PMID:9023924

  13. Focus Sheet | Hydrofluoric Acid Health hazards of hydrofluoric acid

    E-print Network

    Wilcock, William

    Focus Sheet | Hydrofluoric Acid Health hazards of hydrofluoric acid Hydrofluoric acid (HF eye damage. HF vapors can seriously damage the lungs. Pulmonary edema (flooding of the lungs characterized by weight loss, brittle bones, anemia, and general ill health. Safe use If possible, avoid working

  14. Pantothenic acid (Vitamin B5)

    MedlinePLUS

    Pantothenic acid is a vitamin, also known as vitamin B5. It is widely found in both plants and animals ... Vitamin B5 is commercially available as D-pantothenic acid, as well as dexpanthenol and calcium pantothenate, which ...

  15. Molecular Structure of Glutaric acid

    NSDL National Science Digital Library

    2004-11-10

    Glutaric acid is a colorless liquid and white crystals as a solid occurring in plants and animal tissues. It is used in organic synthesis and as an intermediate for the manufacture of polymers such as polyamides and polyesters, ester plasticizers and corrosion inhibitors. It is also useful in the application of decreasing polymer elasticity and in a variety of industrial applications. In addition glutaric acid plays an important role as an intermediary in the Krebs cycle and is used in medication against a large number of viruses and in animal diabetes. Glutaric acid can be prepared from cyclopentanone by oxidative ring fission with nitric acid and in the presence of a catalyst. Glutaric acid has the lowest melting point among dicarboxylic acids (98 C); it is very soluble in water and the solution in water is a medium strong acid. Short-term exposure to glutaric acid may cause irritation to the eyes, skin and the respiratory tract.

  16. Molecular Structure of Maleic acid

    NSDL National Science Digital Library

    2004-11-10

    Maleic acid is colorless to white crystals with a faint acidulous odor and a characteristic repulsive, astringent taste. Maleic acid is used in making polyesters, surface coatings, lubricant additives, agricultural chemicals and paint vehicles. It is used in organic synthesis of fumaric acid, succinic, aspartic, tartaric, propionic, lactic, malonic, acrylic and hydrocarylic acids. Maleic acid and its anhydride are prepared industrially by the catalytic oxidation of benzene. Maleic acid may be released into waste water during its production and used in the manufacture of polymer products. Dust of maleic acid is irritating to the eyes, nose and throat. The general population is exposed to maleic acid in areas with heavy traffic since it is found in aerosols from auto exhaust.

  17. Biochemical composition of organic matter in UK Midlands catchments: implications for drinking water treatment

    Microsoft Academic Search

    M. Bieroza; J. Bridgeman; A. Baker

    2007-01-01

    Insufficient removal of natural organic matter at treatment works can lead to the formation of potentially carcinogenic disinfection by-products (mainly trihalomethanes and haloacetic acids, THMs and HAAs) due to reactions of residual organic matter with chlorine added at the disinfection stage of water treatment process. However, the total organic carbon (TOC) removal efficiency is controlled by the content and character

  18. N e w E n g l a n d W a t e r T r e a t m e n t Technology Assistance Center

    E-print Network

    . In addition, the following process parameters were monitored on a regular basis: total organic carbon, dissolved organic carbon, UV absorbance, flow to each treatment unit, all chemical feeds, clarifier headloss organic matter (BOM), total trihalomethane forming potential and haloacetic acid formation potentials

  19. DBP FORMATION KINETICS IN A SIMULATED DISTRIBUTION SYSTEM

    EPA Science Inventory

    Little is known about how the growth of halogenated disinfection by-products (DBPs) in drinking water is affected by time spent in a distribution system. Experiments were performed to compare the rate of trihalomethane and haloacetic acid production in a simulated pipe environmen...

  20. Using catalytic ozonation and biofiltration to decrease the formation of disinfection by-products

    Microsoft Academic Search

    Kuan-Chung Chen; Yu-Hsiang Wang; Yuan-Huang Chang

    2009-01-01

    The effect of catalytic ozonation in a fluidized bed reactor (FBR) on the formation of individual disinfection by-products (DBPs) was investigated. A biofiltration column was used to evaluate the removal efficiency of biotreatment on DBP precursors. Dissolved organic carbon (DOC), simulated distribution system trihalomethanes (SDS THMs), and six simulated distribution system haloacetic acids (SDS HAA6) were monitored. The source water

  1. REGULATED DRINKING WATER CONTAMINANTS: NEUROTOXIC PROPERTIES

    EPA Science Inventory

    The most common classes of the disinfection by-products (DBPs) encountered in chlorinated systems are regulated with average annual limits for total trihalomethanes (80 µg/liter) and a sum of five of the haloacetic acids (60 µg/liter). Questions persist regarding noncancer health...

  2. Determination of organic compounds in bottled waters

    Microsoft Academic Search

    Stavroula V. Leivadara; Anastasia D. Nikolaou; Themistokles D. Lekkas

    2008-01-01

    The presence of organic compounds in bottled waters available in the Greek market and their fate when the representative samples exposed at different conditions were the main purposes of this study. The determination of the organic compounds was performed by gas chromatography–mass spectrometry techniques. Disinfection by-products compounds, such as trihalomethanes (THMs) and haloacetic acids (HAAs), were detected at low concentrations

  3. BACTERIALLY-MEDIATED DEGRADATION OF A CHIRAL DISINFECTION BYPRODUCT

    EPA Science Inventory

    Disinfection of drinking and waste waters, through chlorination, can result in the production of chlorinated organic compounds, many of which are regulated by the U.S. Environmental Protection Agency. Among these regulated compounds are the haloacetic acids, which exhibit toxic e...

  4. COAGULATION

    EPA Science Inventory

    This chapter reports on the efforts of the USEPA to study conventional and enhanced coagulation for the control of disinfection by-products (DBPs) in drinking water. It examines the control of DBPs like trihalomethanes, haloacetic acids and the surrogate total organic halide in t...

  5. Systems analysis models for disinfection by-product formation in chlorinated drinking water in Ontario

    Microsoft Academic Search

    Edward Mcbean; Zoe Zhu; Wen Zeng

    2008-01-01

    Results of examination of the formation and control of disinfection by-products (DBPs), specifically total trihalomethanes (TTHMs) and total haloacetic acids (HAAs) in water treatment, are described in this article. Systems analysis models for TTHMs and HAAs for drinking water treatment plants using 28 surface water sources in Ontario are developed. Statistically, significant predictive regression models for TTHMs from dissolved organic

  6. Pilot study of the removal of THMs, HAAs and DOC from drinking water by GAC adsorption

    Microsoft Academic Search

    K. G. Babi; K. M. Koumenides; A. D. Nikolaou; C. A. Makri; F. K. Tzoumerkas; T. D. Lekkas

    2007-01-01

    The objective of this pilot study was to evaluate the performance of a GAC postfilter-adsorber for the removal from the drinking water of Athens, Greece, of the two main groups of chlorination by-products, trihalomethanes (THMs) and haloacetic acids (HAAs), as well as of dissolved organic carbon (DOC). The analyses performed during the whole operation period (638 days) showed that the

  7. Uranium (VI) - Chromotropic Acid Chelate

    Microsoft Academic Search

    Samir K. Banerji; Arun K. Dey

    1963-01-01

    DISODIUM- 1:8-dihydroxy naphthalene-3:6-disulphonate (trivial name chromotropic acid-sodium salt)yields coloured lakes with various cations1. Investigations of chelates of chromotropic acid with iron (III)2 and titanium (IV)3,4 have already been made. Sommer et al. have extensively examined chelates of titanium with chromotropic acid and various polyphenols5-7 and have discussed the structure of the metal chelates. The use of chromotropic acid in the

  8. Fatty acid signaling in Arabidopsis

    Microsoft Academic Search

    Edward E. Farmer; Hans Weber; Sabine Vollenweider

    1998-01-01

    .   Many organisms use fatty acid derivatives as biological regulators. In plants, for example, fatty acid-derived signals have\\u000a established roles in the regulation of developmental and defense gene expression. Growing numbers of these compounds, mostly\\u000a derived from fatty acid hydroperoxides, are being characterized. The model plant Arabidopsis thaliana is serving a vital role in the discovery of fatty acid-derived signal

  9. Molecular Structure of Trimesic acid

    NSDL National Science Digital Library

    2003-05-08

    Trimesic Acid is made up of a benzene ring with three carboxylic groups at the 1, 3, and 5 positions, and it can be synthesized from the oxidation of 1,3,5-trimethyl benzene. The acid is an important building block in crystal engineering which is used to form honeycomb structures, but it has the ability to form diverse supramolecular structures. Also, trimesic acid salt and the free trimesic acid are useful as a plasticizer.

  10. Molecular Structure of Acetic acid

    NSDL National Science Digital Library

    2003-06-02

    Acetic Acid commonly associated with vinegar; it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and insecticides. Acetic acid is produced naturally by Aceto bacteria but, except for making vinegar, is usually made through synthetic processes. Ethanoic acid is used as herbicide, as a micro-biocide, as a fungicide and for pH adjustment.

  11. Molecular Structure of Octanoic acid

    NSDL National Science Digital Library

    2002-10-11

    Caprylic acid is a colorless oil manufactured from 1-heptene or 1-octanol. Octanoic acid has an unpleasant rancid taste. When converted from the carboxlic acid to an ester, it has a pleasant taste. In addition, esters of caprylic acid are used in the preparation of dyes, perfumes, and food preservatives. This compound has also been found to have antifungal activity and is used to treat yeast infections.

  12. Acid rain: Reign of controversy

    SciTech Connect

    Kahan, A.M.

    1986-01-01

    Acid Rain is a primer on the science and politics of acid rain. Several introductory chapters describe in simple terms the relevant principles of water chemistry, soil chemistry, and plant physiology and discuss the demonstrated or postulated effects of acid rain on fresh waters and forests as well as on statuary and other exposed objects. There follow discussions on the economic and social implications of acid rain (for example, possible health effects) and on the sources, transport, and distribution of air pollutants.

  13. Enviropedia: Introduction to Acid Rain

    NSDL National Science Digital Library

    This resource provides information about acid rain, a widespread term used to describe all forms of acid precipitation. The sources, nature, and chemistry of acid rain are discussed, along with its impact on buildings, soils, freshwater lakes, trees, and wildlife. Other topics include measuring, modeling, and monitoring acid rain; and vehicle and industrial emission controls. The problem of airborne pollutants migrating across international borders is also discussed.

  14. Factors Controlling Naphthenic Acid Corrosion

    Microsoft Academic Search

    Alan Turnbull; Evelina Slavcheva; Bryan Shone

    1998-01-01

    A laboratory study was conducted to elucidate the influence of chemical and physical parameters on corrosion of type 1018 carbon steel (CS, UNS G10180) and 5% Cr-0.5% Mo steel in oils containing naphthenic acids (NAs) for application to crude oil refinery systems. Effects of test duration, temperature, and acid concentration were assessed for a range of single acids of varying

  15. Nucleic Acids Molecular Biology Tools

    E-print Network

    Qiu, Weigang

    Nucleic Acids Proteins Molecular Biology Tools Molecular Biology and Genomics Weigang Qiu Weigang Qiu Molecular Biology and Genomics #12;Nucleic Acids Proteins Molecular Biology Tools Outline 1 Nucleic Acids 2 Proteins 3 Molecular Biology Tools Weigang Qiu Molecular Biology and Genomics #12;Nucleic

  16. CHARACTERISTICS Picric acid is a

    E-print Network

    Wilcock, William

    CHARACTERISTICS · Picric acid is a trinitroaromatic compound that is a flammable solid when purchased wet with 30% water, by mass. · Picric acid is a high-powered explosive when allowed to dehydrate. As an explosive, picric acid is not shock sensitive, but when in contact with metals can form shock sensitive

  17. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C.J.; Poole, L.J.

    1995-05-02

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine. 10 figs.

  18. A ACID RAIN Audrey Gibson

    E-print Network

    Toohey, Darin W.

    A ACID RAIN Audrey Gibson ATOC 3500 Thursday, April 29, 2010 #12;CAUSES Natural sources - volcanoes Thursday, April 29, 2010 #12;ON WILDLIFE Acid rain causes acidification of lakes and streams and contributes to damage of trees at high elevations. Acid rain primarily affects sensitive bodies of water

  19. An Umbrella for Acid Rain.

    ERIC Educational Resources Information Center

    Randal, Judith

    1979-01-01

    The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)

  20. Do We Need Gastric Acid?

    Microsoft Academic Search

    D. Pohl; M. Fox; M. Fried; B. Göke; C. Prinz; H. Mönnikes; G. Rogler; M. Dauer; J. Keller; F. Lippl; I. Schiefke; U. Seidler; H. D. Allescher

    2008-01-01

    Evidence from comparative anatomy and physiology studies indicates that gastric acid secretion developed during the evolution of vertebrates approximately 350 million years ago. The cellular mechanisms that produce gastric acid have been conserved over the millennia and therefore proton pump inhibitors have pharmacological effects in almost all relevant species. These observations suggest that gastric acid provides an important selective advantage;

  1. Pantothenic acid biosynthesis in zymomonas

    DOEpatents

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  2. BACTERIAL OXIDATION OF DIPICOLINIC ACID

    PubMed Central

    Kobayashi, Yasuo; Arima, Kei

    1962-01-01

    Kobayashi, Yasuo (University of Tokyo, Tokyo, Japan) and Kei Arima. Bacterial oxidation of dipicolinic acid. II. Identification of ?-ketoglutaric acid and 3-hydroxydipicolinic acid and some properties of cell-free extracts. J. Bacteriol. 84:765–771. 1962—When a dipicolinic acid (DPA)-decomposing bacterium, Achromobacter strain 1–2, was incubated at 30 C with shaking in a DPA solution containing 10?3m arsenite, a keto acid was accumulated. The 2,4-dinitrophenylhydrazone of this acid was synthesized and identified as ?-ketoglutaric acid by paper chromatography, visible absorption spectrum, infrared analysis, elemental analysis, and mixed melting point. During this incubation, oxalic acid equivalent to the consumed dipicolinic acid was produced. A fluorescent material was also isolated from culture fluid and identified as 3-hydroxydipicolinic acid by paper chromatography and the ultraviolet absorption spectrum. Further, cell-free extracts were prepared by sonic oscillation. Ferrous ion and a reduced di- or triphosphopyridine nucleotide-generating system were proven to be required for enzymic oxidation of DPA. And 3-hydroxydipicolinic acid was also oxidized by this preparation. From the results obtained, a possible metabolic pathway of dipicolinic acid was proposed. PMID:14033954

  3. Weak Acid Equilibrium

    NSDL National Science Digital Library

    michael stapleton

    Students are asked to calculate the pH of a weak acid aqueous solution. The problems involve a series of generic acids with assigned equilibrium constants (Ka) and total concentrations (Ct). Initially, students are required to hand calculate all problems by algebraic manipulation of the mathematical relationships of the system. The solution is a cubic equation. Through a series of assumptions, the solution is simplified. The assumptions are based on the chemistry of the system given the Ka and Ct for the problem. The problems are then graphically solved. Ultimately, the students develop an Excel worksheet to solve the problems and a Bjerrum plot to display the speciation as a function of pH.

  4. Nucleic Acid Detection Methods

    Microsoft Academic Search

    Cassandra L. Smith; Ron Yaar; Przemyslaw Szafranski; Charles R. Cantor

    1998-01-01

    The invention relates to methods for rapidly determining the sequence and\\/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3'-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be

  5. Nucleic acid detection methods

    Microsoft Academic Search

    C. L. Smith; R. Yaar; P. Szafranski; C. R. Cantor

    1998-01-01

    The invention relates to methods for rapidly determining the sequence and\\/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3â²-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be

  6. Acid Rain Effects

    NSDL National Science Digital Library

    2014-06-30

    Learners conduct a simple experiment to model and explore the harmful effects of acid rain (vinegar) on living (green leaf and eggshell) and non-living (paper clip) objects. Learners observe the effects over a period of days. This activity has links to other activities which can be combined to make a larger lesson. Resource contains vocabulary definitions and suggestions for assessment, extensions, and scaling for different levels of learners.

  7. Acid rain in Asia

    Microsoft Academic Search

    Neeloo Bhatti; David G. Streets; Wesley K. Foell

    1992-01-01

    Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to\\u000a the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging\\u000a perception that the problem in these Western nations is nearing solution. The situation in

  8. Fatty Acid Carcass Mapping

    E-print Network

    Turk, Stacey N.

    2010-01-14

    ) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types and backgrounds were sampled. External fat samples were collected from eight different carcass locations: round, sirloin, loin, rib... was the lowest. Due to the significant differences amongst fat depots within bovine carcasses in their fatty acid composition we conclude that substantial differences exist across fat depots. v DEDICATION...

  9. Cannabinoid acids analysis.

    PubMed

    Lercker, G; Bocci, F; Frega, N; Bortolomeazzi, R

    1992-03-01

    The cannabinoid pattern of vegetable preparations from Cannabis sativa (hashish, marijuana) allows to recognize the phenotype of the plants, to be used as drug or for fiber. Cannabinoid determination by analytical point of view has represented some problems caused by the complex composition of the hexane extract. Capillary gas chromatography of the hexane extracts of vegetable samples, shows the presence of rather polar constituents that eluted, with noticeable interactions, only on polar phase. The compounds can be methylated by diazomethane and silanized (TMS) by silylating reagents. The methyl and methyl-TMS derivatives are analyzed by high resolution gas chromatography (HRGC) and by gas chromatography-mass spectrometry (GC-MS). The identification of the compounds shows their nature of cannabinoid acids, which the main by quantitative point of view results the cannabidiolic acid (CBDA). It is known that the cannabinoid acids are thermally unstable and are transformed in the corresponding cannabinoids by decarboxilation. This is of interest in forensic analysis with the aim to establish the total amount of THC in the Cannabis preparations, as the active component. PMID:1503600

  10. Degradation of Phthalic Acids and Benzoic Acid from Terephthalic Acid Wastewater by Advanced Oxidation Processes

    Microsoft Academic Search

    Ramesh Thiruvenkatachari; Tae Ouk Kwon; Il Shik Moon

    2006-01-01

    Terephthalic acid (TPA) wastewater is traditionally being treated by biological method. This study investigates the degradation of three major toxic target organic species, namely terephthalic acid (TPA), isophthalic acid (IPA), benzoic acid (BA), present in the TPA wastewater, by several advanced oxidation processes. The performance of three main oxidation processes such as photofenton oxidation (UV-H2O2-Fe), photocatalytic ozonation (UV-O3-Fe) and photofenton

  11. Invasive cleavage of nucleic acids

    DOEpatents

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  12. Invasive cleavage of nucleic acids

    DOEpatents

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2002-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  13. Molecular Structure of Benzoic acid

    NSDL National Science Digital Library

    2003-05-08

    Benzoic acid is a medium-strong acid found in human foods such as berries, and is used as a plasticizer, insecticide, fungicide, an antifungal agent and in the manufacture of pharmaceuticals. It is more hydrophobic, water fearing, in comparison with other carboxylic acids and therefore can be extracted easily from all types of solvents. This acid is slightly soluble in water and has a melting point of 122 degrees Celsius. Benzoic acid is industrially manufactured from toluene, benzotrichloride and phthalic anhydride. It is purified by the process of sublimation, and the extremely pure form is used as a titrimetric and calorimetric standard in analytical chemistry.

  14. Molecular Structure of Adipic acid

    NSDL National Science Digital Library

    2004-11-09

    Adipic acid is odorless and colorless white crystals or powder with a sour taste. Adipic acid is used primarily in the manufacture of nylon-6,6 polyamide and polyester polyols for polyurethane systems. It is also used for raw materials in pharmaceuticals, perfume fixatives, acidulants, leavening and buffering agents in non-alcoholic beverages, gelatins and puddings. In addition, adipic acid is used in manufacturing plasticizers and lubricants components. It is slightly soluble in water and soluble in alcohol and acetone. Adipic acid can be prepared from acetylene and acetic acid in the presence of tert-butyl peroxide. It has been manufactured from either cyclohexane or phenol.

  15. The politics of acid rain

    SciTech Connect

    Wilcher, M.E. (Pennsylvania State Univ., New Kensington, PA (US))

    1989-01-01

    This work examines and compares the acid rain policies through the different political systems of Canada, Great Britain and the United States. Because the flow of acid rain can transcend national boundaries, acid rain has become a crucial international problem. According to the author, because of differences in governmental institutions and structure, the extent of governmental intervention in the industrial economy, the degree of reliance on coal for power generation, and the extent of acid rain damage, national responses to the acid rain problem have varied.

  16. Acid Rain Experiments: Soil Buffering

    NSDL National Science Digital Library

    This experiment will help students understand that soil sometimes contains substances, like limestone, that buffer acids or bases, and that some salts in soil may also act as buffers. They will collect soil samples from their lawn, garden, or school and look for buffering effects by observing the pH change of an acid mixture poured through the samples. If the water collected from the sample is less acidic than the original mixture, then the soil is buffering some of the acid. If it does not change, then the soil may not be capable of buffering acids.

  17. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  18. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  19. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  20. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...

  1. Effect of diets rich in oleic acid, stearic acid and linoleic acid on postprandial haemostatic factors in young healthy men

    Microsoft Academic Search

    Kirsty A. Hunter; Lynn C. Crosbie; Graham W. Horgan; George J. Miller; Asim K. Dutta-Roy

    2001-01-01

    The aim of the present study was to investigate the effects of stearic acid-, oleic acid- and linoleic acid-rich meals on postprandial haemostasis in young healthy volunteers whose background diets had been controlled for 14 d in a residential study. Six healthy male volunteers were assigned randomly to consume diets rich in stearic acid, oleic acid or linoleic acid for

  2. Molecular Structure of Picric acid

    NSDL National Science Digital Library

    2002-09-23

    Picric Acid was first discovered in 1771 by a British Chemist named Peter Woulfe by treatment of indigo with nitric acid. It is most commonly seen in its yellow, water-soluble, crystalline form. For this reason, picric acid first saw use as a dyeing agent in textiles. However, around 1849 it was discovered (for obvious reasons) that picric acid is a shock, heat, and friction-sensitive explosive. Its first use as an explosive material came in military weaponry: torpedoes in particular due to its shock-sensitive nature not requiring a detonator to explode on contact with a target. However, picric acid was found to be highly corrosive to metals, making the weapons very difficult to handle and the acid itself difficult to store. Today, picric acid is used more widely as an ingredient in the manufacture of inert dyes and stable explosives such as dynamite.

  3. Molecular Structure of Sorbic acid

    NSDL National Science Digital Library

    2004-11-11

    Sorbic acid is a colorless or white crystalline powder, with a weak characteristic odor and slightly acidic taste. It may be obtained from berries of the mountain ash or prepared synthetically by condensing crotonaldehyde and malonic acid in pyridine solution. Sorbic acid is a polyunsaturated fat used to inhibit molds and yeast, is a fungistatic agent for foods (especially cheeses, wine and baked goods). The main use of sorbic acid is as a preservative in foods, animal feeds, tobacco, cosmetics and pharmaceuticals, as well in packing materials for these substances and in other products that come in contact with human or animal skin in some way. Sorbic acid is also used as an intermediate for plasticizers and lubricants. Sorbic acid reacts with potassium to make potassium sorbate and with calcium to make calcium sorbate.

  4. Esterification by the Plasma Acidic Water: Novel Application of Plasma Acid

    NASA Astrophysics Data System (ADS)

    Gu, Ling

    2014-03-01

    This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.

  5. Lipid metabolism in the perfused chicken liver. The uptake and metabolism of oleic acid, elaidic acid, cis-vaccenic acid, trans-vaccenic acid and stearic acid

    PubMed Central

    Bickerstaffe, R.; Annison, E. F.

    1970-01-01

    Comparative studies were made of the uptake and metabolism of cis- and trans-octadecenoic acids by the perfused chicken liver. No differences were observed in the rates of uptake of the isomers. There was considerable incorporation of radioactivity into triglycerides and phospholipids, and some release of labelled lipid into the perfusate was observed. The cis-fatty acids were more readily incorporated into triglycerides than phospholipids, the reverse being true of the trans-fatty acids. Examination of the intramolecular distribution of fatty acids in triglycerides showed that the trans-fatty acid and stearate mainly occupied the 1- and 3-positions, and cis-fatty acids the 2-position. In the phospholipids phosphatidylcholine and phosphatidylethanolamine the trans-fatty acids again behaved like stearic acid and favoured the 1-position. No evidence was obtained of atypical patterns of uptake or metabolism of the trans-fatty acids. PMID:5472169

  6. Vibrational structure of the polyunsaturated fatty acids eicosapentaenoic acid and arachidonic acid studied by infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Kiefer, Johannes; Noack, Kristina; Bartelmess, Juergen; Walter, Christian; Dörnenburg, Heike; Leipertz, Alfred

    2010-02-01

    The spectroscopic discrimination of the two structurally similar polyunsaturated C 20 fatty acids (PUFAs) 5,8,11,14,17-eicosapentaenoic acid and 5,8,11,14-eicosatetraenoic acid (arachidonic acid) is shown. For this purpose their vibrational structures are studied by means of attenuated total reflection (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The fingerprint regions of the recorded spectra are found to be almost identical, while the C-H stretching mode regions around 3000 cm -1 show such significant differences as results of electronic and molecular structure alterations based on the different degree of saturation that both fatty acids can be clearly distinguished from each other.

  7. Metabolism of 14 C-labelled oleic acid, erucic acid and nervonic acid in rats

    Microsoft Academic Search

    K. K. Carroll

    1966-01-01

    1-14C-Oleic acid, 2-14C-erucic acid and 2-14C-nervonic acid were administered to rats by tail-vein and the distribution of radioactivity in liver lipids was determined\\u000a at intervals from 15 min to 6 hr after injection. High levels of activity were found after short time intervals which were\\u000a mainly associated with triglycerides in the case of oleic acid and with free fatty acids

  8. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Technical Reports Server (NTRS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-01-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  9. Bile Acid Metabolism and Signaling

    PubMed Central

    Chiang, John Y. L.

    2015-01-01

    Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684

  10. Biophysical Properties of Phenyl Succinic Acid Derivatised Hyaluronic Acid

    Microsoft Academic Search

    Maria Teresa Neves-Petersen; Søren Klitgaard; Esben Skovsen; Steffen B. Petersen; Kristoffer Tømmeraas; Khadija Schwach-Abdellaoui

    2010-01-01

    Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared\\u000a to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic\\u000a materials. In the present study, hyaluronic acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA).\\u000a The fluorescence

  11. Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells

    Microsoft Academic Search

    Yao Zhang; Rui-Dong Duan

    2009-01-01

    BACKGROUND: Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase) has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes. METHODS: The present study is to examine the effect of 3-acetyl-11-keto-?-boswellic acids (AKBA), a potent

  12. Modification of hyaluronic acid with aromatic amino acids

    Microsoft Academic Search

    I. Yu. Ponedel’kina; V. N. Odinokov; E. S. Vakhrusheva; M. T. Golikova; L. M. Khalilov; U. M. Dzhemilev

    2005-01-01

    Hyaluronic acid was modified with aromatic amino acids (5-aminosalicylic, 4-aminosalicylic, anthranilic, and p-aminobenzoic) in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide. The modified glycans contained 9–43% of arylamide groups and 10–33% of isoureidocarbonyl groups depending on the nature of the amino acid. Reduction with sodium borohydride allowed the conversion of isoureidocarbonyl groups into hydroxymethyl groups.

  13. Molecular Structure of Phosphoric acid

    NSDL National Science Digital Library

    2002-09-10

    Phosphoric acid was first made in 1774 by K.W. Scheele and J.G. Gahn from bone ash. Phosphoric acid is made by treating calcium phosphate rock with sulfuric acid, followed by filtration. It is by this process that almost 10 tons of phosphoric acid are produced in the United States each year. The compound is primarily used to manufacture some pharmaceutical products, fertilizers and as a flavoring agent in coca-cola. The steel industry uses it to clean and rust-proof their steel. Phosphoric acid is also used in the process of soil stabilization, and as a catalyst in the production of propylene and butene polymers, ethylbenzene, and cumene. In recent years though the industry has moved away from using phosphoric acid as a ingredient in detergents because of the harmful effect that Phosphates have on lakes a process called lake eutrophication.

  14. Molecular Structure of Butyric acid

    NSDL National Science Digital Library

    2002-10-11

    n-Butyric acid is a substance that was isolated from butter in 1869. Butyric acid means, in Latin, the acid of butter as it was first discovered in rancid butter. It is found most commonly in butter, but can also be present in some fruits. Butyric acid is also produced synthetically, through fermentation of various carbohydrates, to be used as a flavoring agent in various food products. Applications of butyric acid are as an additive to food, flavorings, varnishes, perfumes, pharmaceuticals and disinfectants. It is also used for the production of plastics, plasticizers, surfactants and textile auxiliaries. Butyric acid and its derivatives are also being seriously considered around the world as potential anticancer agents.

  15. Butyric acid in functional constipation

    PubMed Central

    Pituch, Aleksandra; Walkowiak, Jaros?aw

    2013-01-01

    Butyric acid, a short-chain fatty acid, is a major energy source for colonocytes. It occurs in small quantities in some foods, and in the human body, it is produced in the large intestine by intestinalkacteria. This production can be reduced in some cases, for which butyric acid supplementation may be useful. So far, the use of butyric acid in the treatment of gastrointestinal disorders has been limited because of its specific characteristics such as its rancid smell and rapid absorption in the upper gastrointestinal tract. In the Polish market, sodium butyrate has been recently made available, produced by the modern technology of microencapsulation, which allows the active substance to reach the small and large intestines, where butyrate easily dissociates into butyric acid. This article presents the potential beneficial mechanisms of action of butyric acid in defecation disorders, which are primarily associated with reductions in pain during defecation and inflammation in the gut, among others. PMID:24868272

  16. Aqueous solubility and acidity constants of cholic, deoxycholic, chenodeoxycholic, and u rsodeoxyc ho I ic acids

    Microsoft Academic Search

    Yoshikiyo Moroi; Hideaki Itoh

    Cholic acid, deoxycholic acid, chenodeoxycholic acid, and ursodeoxycholic acid were purified by a foam frac- tionation method. Using thermogravimetric analysis, the at- tached water molecule was found to be completely removed from solids of the latter three at 100°C, while cholic acid still had one water molecule of crystallization per two cholic acid molecules at that temperature. The acidity constants

  17. Zirconium in sulfuric acid applications

    SciTech Connect

    Webster, R.T.; Yau, T.L.

    1986-02-01

    Zirconium is one of the few metals that resists attack by sulfuric acid at concentrations up to 75% and temperatures to boiling and above. This capability makes zirconium a good structural metal for use in 40 to 65% H/sub 2/SO/sub 4/ up to boiling temperatures and for weak acid concentrations at elevated temperatures. Zirconium's corrosion properties in sulfuric acid solutions are compared with nickel base alloys. Examples of applications and limitations in the use of zirconium are presented.

  18. Intestinal metabolism of fatty acids

    PubMed Central

    Enser, M.

    1965-01-01

    1. The effect of concentration on the oxidation and incorporation into lipids of lauric acid and linoleic acid by rings of rat small intestine has been studied in vitro. 2. In the absence of glucose, the oxidation of lauric acid in the range 0·01–5·0mm showed a maximum at 0·1mm. In the presence of glucose the maximum was at 0·5mm. The oxidation of linoleic acid in the presence of glucose increased throughout the concentration range 0·01–5·0mm. 3. The incorporation of lauric acid into lipids was maximal at 0·5–0·6mm in the presence of glucose, but at 10mm in the absence of glucose. At 0·8mm-lauric acid, in the presence of glucose, over 75% of the incorporated lauric acid was in triglycerides, but at 10mm they only contained 30%. The incorporation of glucose carbon into glycerides paralleled the incorporation of lauric acid. 4. In the range 0·01–2·5mm-linoleic acid the quantity incorporated into lipids increased. In the range 0·01–0·4mm linoleic acid was incorporated predominantly into triglycerides, but between 0·4 and 1·0mm most was in diglycerides, and between 2·5 and 5·0mm most was in monoglycerides. 5. The relationship of fatty acid concentration to the mechanism of absorption is discussed, together with the correlation between the distribution of the absorbed fatty acids within the tissue lipids and the lipase activity of intestinal mucosa. PMID:5837779

  19. Piezoelectricity in protein amino acids

    NASA Astrophysics Data System (ADS)

    Lemanov, V. V.; Popov, S. N.; Pankova, G. A.

    2011-06-01

    The piezoelectric activity of protein amino acids and their compounds has been measured using the pulse method at a frequency of 10 MHz. It has been established that, at room temperature, the piezoelectric effect is not observed in ?-glycine (achiral amino acid) and protein amino acids of the L modification, namely, methionine, phenylalanine, and tryptophan. An assumption has been made that this phenomenon is associated with the enhanced damping of elastic vibrations excited in samples due to the piezoelectric effect.

  20. New syntheses of aminoalkylphosphonic acids 

    E-print Network

    DeBardeleben, John Frederick

    1963-01-01

    to remove any remaining benzoic acid, The aqueous layer was evaporated on a steam bath in vacuum. To the residue 100 ml, of ethyl alcohol was added. The resulting mixture was filtered while hot to remove sodium chloride. The alcohol was removed by dis.... Only three ? valine (VIII a), leucine (VIII b), and isoleucine (VIII c) ? corresponded to naturally occurring amino carboxylic acids. Mono- and dialkylmalonamidic acids (IX) were caused to react with sodium hypobromite, yielding the desired amino...

  1. Acid site promotion of mordenite

    Microsoft Academic Search

    W. J. Kiovsky; J. R. Goyette; T. M. Notermann

    1978-01-01

    Ammonia adsorption isotherms for H-mordenite (10:1 silica-alumina) and partially dealuminated H-mordenite (13:1 silica-alumina) showed that dealumination generated new strong acid sites, in contrast to dealumination of Y-zeolite, which decreases first the weak and then the stronger acid sites. An IR spectroscopic study of 13:1 and 16:1 silica-alumina mordenites showed that the number of both Lewis and Broensted strong acid sites

  2. Alkali-isomerized linoleic acid

    Microsoft Academic Search

    D. E. Terry; D. H. Wheeler

    1946-01-01

    Summary  Alkali-isomerized linoleic acid and its methyl ester have been found to have boiling points higher than the corresponding\\u000a normal C18 acids and esters.\\u000a \\u000a By careful fractional distillation of methyl esters of alkali-isomerized C18 cottonseed acids, methyl linoleate of 95% or more purity is obtained consisting of 75% conjugated methyl linoleate and some\\u000a 20% of methyl ester of an altered linoleic

  3. Fumaric acid production by fermentation

    Microsoft Academic Search

    Carol A. Roa Engel; Adrie J. J. Straathof; Tiemen W. Zijlmans; Walter M. van Gulik; Luuk A. M. van der Wielen

    2008-01-01

    The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric\\u000a acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical\\u000a process yields 112% w\\/w fumaric acid from maleic anhydride and the fermentation process yields only 85% w\\/w from glucose, the latter raw

  4. Molecular Structure of Propionic acid

    NSDL National Science Digital Library

    2002-10-11

    Propanoic acid was named after the Greek word "Pro" for first and "pion" for fat, because it is the first fatty acid. It is a liquid and has a slightly pungent odor that can be characterized as rancid. Sweat, milk, and fermentation products all contain small amounts of this chemical. It can be synthesized from ethanol or ethylene and carbon monoxide. The calcium salt of propanoic acid is used as an antimolding agent and is an additive in breads. Esters of this carboxylic acid have a pleasant smell and taste and are used in the manufacture of fruit flavors and perfume bases. This compound is also found in a herbicide, called Silverado.

  5. Acid pulses from snowmelt at acidic cone pond, New Hampshire

    Microsoft Academic Search

    S. Fay Baird; Donald C. Buso; James W. Hornbeck

    1987-01-01

    A study was undertaken to examine whether ‘acid pulses’ from snowmelt created permanent changes in a pond's chemistry. Water samples were collected from clearwater acidic Cone Pond in the White Mountain National Forest, New Hampshire. The pond, inlet, and outlet were intensively sampled throughout winter and early spring 1983–84. Thaws brought more H+ into upper waters of the pond, but

  6. Naphthenic acids and surrogate naphthenic acids in methanogenic microcosms

    Microsoft Academic Search

    Fervone M Holowenko; Michael D MacKinnon; Phillip M Fedorak

    2001-01-01

    Naphthenic acids (NAs) are a complex mixture of naturally occurring acyclic and cyclic aliphatic carboxylic acids in petroleum. In the Athabasca oil sands, NAs have been identified as the largest component of dissolved organic matter in the tailings waters from oils sands extraction processes. They are the major contributor to the acute toxicity of the fine tailings wastewaters at the

  7. Acid zeta function and ajoint acid zeta function

    E-print Network

    Jining Gao

    2010-03-16

    In this paper we set up the theory of acid zeta function and ajoint acid zeta function, based on the theory, we point out a reason to doubt the truth of the Riemann hypothesis and also as a consequence, we give out some new RH equivalences.

  8. No Potassium, No Acid: K+ Channels and Gastric Acid Secretion

    NSDL National Science Digital Library

    2007-10-01

    The gastric H+-K+-ATPase pumps H+ into the lumen and takes up K+ in parallel. In the acid-producing parietal cells, luminal KCNE2/KCNQ1 K+ channels play a pivotal role in replenishing K+ in the luminal fluid. Inactivation of KCNE2/KCNQ1 channels abrogates gastric acid secretion and dramatically modifies the architecture of gastric mucosa.

  9. Acid rain on acid soil: a new perspective

    Microsoft Academic Search

    E. C. Krug; C. R. Frink

    1983-01-01

    Acid rain is widely believed to be responsible for acidifying soil and water in areas of North America and northern Europe. However, factors commonly considered to make landscapes susceptible to acidification by acid rain are the same factors long known to strongly acidify soils through the natural processes of soil formation. Recovery from extreme and widespread careless land use has

  10. 40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721...Substances § 721.10679 Carboxylic acid, substituted alkylstannylene...

  11. A Simpler Nucleic Acid

    NASA Technical Reports Server (NTRS)

    Orgel, Leslie

    2000-01-01

    It has been supposed that for a nucleic acid analog to pair with RNA it must, like RNA, have a backbone with at least a sixatom repeat; a shorter backbone presumably would not stretch far enough to bind RNA properly. The Eschenmoser group has shown, however, that this first impression is incorrect.As they report in their new paper, Eschenmoser and co-workers ( I ) have now synthesized a substantial number of these polymers, which are called (L)-a-threofuranosyl oligonucleotides or TNAs. They are composed of bases linked to a threose sugar-phosphate backbone, with phosphodiester bonds connecting the nucleotides. The investigators discovered that pairs of complementary TNAs do indeed form stable Watson-Crick double helices and, perhaps more importantly, that TNAs form stable double helices with complementary RNAs and DNAs.

  12. Acid rain on acid soil: a new perspective

    SciTech Connect

    Krug, E.C.; Frink, C.R.

    1983-08-05

    Acid rain is widely believed to be responsible for acidifying soil and water in areas of North America and Northern Europe. However, factors commonly considered to make landscapes susceptible to acidification by acid rain are the same factors long known to strongly acidify soils through the natural processes of soil formation. Recovery from extreme and widespread careless land use has also occurred in regions undergoing acidification. There is evidence that acidification by acid rain is superimposed on long-term acidification induced by changes in land use and consequent vegetative succession. Thus, the interactions of acid rain, acid soil, and vegetation need to be carefully examined on a watershed basis in assessing benefits expected from proposed reductions in emissions of oxides of sulfur and nitrogen.

  13. Microbial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.

    PubMed Central

    Zürrer, D; Cook, A M; Leisinger, T

    1987-01-01

    Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein. A Pseudomonas sp., an Arthrobacter sp., and an unidentified bacterium were examined. Each desulfonated at least 16 aromatic compounds, none of which served as a carbon source. Pseudomonas sp. strain S-313 converted 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, benzenesulfonic acid, and 3-aminobenzenesulfonic acid to 1-naphthol, 2-naphthol, 5-amino-1-naphthol, phenol, and 3-aminophenol, respectively. Experiments with 18O2 showed that the hydroxyl group was derived from molecular oxygen. PMID:3662502

  14. Octadecylsulfuric acid. Properties of the acid, amine salts, and salts of amino acids

    Microsoft Academic Search

    E. W. Maurer; A. J. Stirton; J. K. Weil

    1960-01-01

    Summary  Octadecanol, hexadecanol, tetradecanol, and dodecanol were sulfated with chlorosulfonic acid, and the corresponding alkylsulfuric\\u000a acids were isolated in a pure state as white crystalline solids with definite melting points.\\u000a \\u000a Octadecylsulfuric acid resembles sodium octadecyl sulfate in detergent and surface-active properties and in stability to hydrolysis\\u000a at equal concentrations of hydrogen ion. It is more soluble in water than sodium octadecyl

  15. Determination of relative acid strength and acid amount of solid acids by Ar adsorption

    Microsoft Academic Search

    Hiromi Matsuhashi; Ayumi Futamura

    2006-01-01

    Relative acid strength and acid amount of solid acids (alumina, silica-alumina, sulfated zirconia, mordenite, ZSM-5, beta, Y, and reduced MoO3) are determined by argon adsorption technique. To obtain the heat of Ar adsorption and saturated adsorption amount, the adsorption isotherm is analyzed using the theory reported by Cremer and Flügge. The obtained heats of Ar adsorption and saturated adsorption amounts

  16. Carbonic Acid Pretreatment of Biomass

    SciTech Connect

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. 6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high (~50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.

  17. Carbonic Acid Retreatment of Biomass

    SciTech Connect

    Baylor university

    2003-06-01

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. (6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high ({approx}50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.

  18. Individual Particle Morphology and Acidity

    Microsoft Academic Search

    Esther Coz; Begoña Artíñano; Allen L. Robinson; Gary S. Casuccio; Traci L. Lersch; Spyros N. Pandis

    2008-01-01

    The morphological characterization of particles during the Pittsburgh Air Quality Study (PAQS) suggests that particle shape and physical state depends on their acidity. The aerosol shape parameters measured by Computer-Controlled Scanning Electron Microscopy (CCSEM) are statistically different in periods when atmospheric particles are neutral and when they are acidic. High concentrations of particles smaller than 500 nm with high sulfur

  19. Molecular Structure of Formic acid

    NSDL National Science Digital Library

    2003-05-08

    Formic Acid, also known as methanoic acid and hydrogencarboxylic acid, is the simplest organic acid. It is a colorless, toxic, corrosive liquid with a pungent, penetrating odor. In nature, it is found in the stings and bites of many insects of the order hymenoptera, including bees and ants. The principal use of formic acid is as a preservative and antibacterial agent in livestock feed. The largest single use of formic acid is as a silage additive in Europe, but this market hardly exists in the United States. When sprayed on fresh hay or other silage, it arrests certain decay processes and causes the feed to retain its nutritive value longer. In the poultry industry, it is sometimes added to silage to kill salmonella bacteria. It is also used in textile dyeing, leather tanning, as a solvent, in electroplating processes, in the manufacturing of lacquers, glass, vinyl resin plasticizers, and formate esters (for flavor and fragrance) and in the manufacture of fumigants. Formic acid is a strong reducing agent, and may act both as an acid and as an aldehyde because the carboxyl is bound to a hydrogen rather than an alkyl group.

  20. SOIL REACTION AND ACIDIC DEPOSITION

    EPA Science Inventory

    This chapter discusses the major chemical processes by which acidic deposition interacts with soils. he focus is on forest soils, as the effects of acidic deposition on soils used for production of food and fiber are generally small compared to effects of agricultural practices s...

  1. Getting Back to Basics (& Acidics)

    ERIC Educational Resources Information Center

    Rhodes, Sam

    2006-01-01

    This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…

  2. The Acid Rain Differential Game

    Microsoft Academic Search

    Karl-Göran Mäler; Aart De Zeeuw

    1998-01-01

    This paper considers an acid rain differential game. Countries emit sulphur which is partly transferred to other countries. Depositions above critical loads ultimately destroy the soil. Countries face a trade-off between the costs of emission reductions and the damage to the soil due to the depletion of the acid buffers. Because of the transboundary externalities the outcome will depend on

  3. Acid rain & electric utilities II

    SciTech Connect

    NONE

    1997-12-31

    This document presents reports which were presented at the Acid Rain and Electric Utilities Conference. Topics include environmental issues and electric utilities; acid rain program overview; global climate change and carbon dioxide; emissions data management; compliance; emissions control; allowance and trading; nitrogen oxides; and assessment. Individual reports have been processed separately for the United States Department of Energy databases.

  4. Acid Rain: The Scientific Challenge.

    ERIC Educational Resources Information Center

    Godfrey, Paul J.

    1991-01-01

    Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)

  5. Acid Precipitation: Causes and Consequences.

    ERIC Educational Resources Information Center

    Babich, Harvey; And Others

    1980-01-01

    This article is the first of three articles in a series on the acid rain problem in recent years. Discussed are the causes of acid precipitation and its consequences for the abiotic and biotic components of the terrestrial and aquatic ecosystems, and for man-made materials. (Author/SA)

  6. Acid Rain: What's the Forecast?

    ERIC Educational Resources Information Center

    Bybee, Rodger

    1984-01-01

    Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

  7. Acid Rain: An Educational Opportunity?

    ERIC Educational Resources Information Center

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  8. SIMULATED ACID RAIN ON CROPS

    EPA Science Inventory

    In 1981, simulated H2SO4 acid rain was applied to alfalfa and tall fescue and a 2:1 ratio of H2SO4:HNO3 acid rain was applied to alfalfa, tall fescue, barley, wheat, potato, tomato, radish, and corn crops growing in the open field at Corvallis, Oregon. Careful attention was given...

  9. Concise Synthesis of Ximenynic Acid

    Microsoft Academic Search

    Lutai Wang; Jiabin Li; Xiaowen Xue

    2012-01-01

    An improved synthesis of ximenynic acid (1) starting from castor oil has been developed with the direct chlorination of ricinstearolic acid as the key step. By this modification, the synthetic route was more concise and economic. The separation of geometric somers was achieved by repeated urea fractionation.Supplemental materials are available for this article. Go the publisher's online edition of Synthetic

  10. Preparation of pure stearic acid

    Microsoft Academic Search

    J. M. Philipson; M. J. Heldman; L. L. Lyon; R. D. Vold

    1944-01-01

    N order to interpret data on commercial soaps it is frequently necessary to investigate the behavior of systems of single pure soaps. For significant results, this often necessitates the preparation of purer fatty acids than any which can be purchased. Although there are numerous (1, 2) descriptions in the literature of methods for the preparation of pure stearic acid these

  11. Functional nucleic acid probes and uses thereof

    DOEpatents

    Nilsen-Hamilton, Marit

    2006-10-03

    The present invention provides functional nucleic acid probes, and methods of using functional nucleic acid probes, for binding a target to carry out a desired function. The probes have at least one functional nucleic acid, at least one regulating nucleic acid, and at least one attenuator. The functional nucleic acid is maintained in an inactive state by the attenuator and activated by the regulating nucleic acid only in the presence of a regulating nucleic acid target. In its activated state the functional nucleic acid can bind to its target to carry out a desired function, such as generating a signal, cleaving a nucleic acid, or catalyzing a reaction.

  12. Combined Acid Catalysis for Asymmetric Synthesis

    E-print Network

    Johnson, Jeff S.

    Combined Acid Catalysis for Asymmetric Synthesis Michael T. Corbett University of North Carolina, 44, 1924­1942. Limitations of classical Brønsted/Lewis Acid catalysis: · Poor reactivity (low acidity) · Low selectivity · High catalyst loading R X R X HMLn X Lewis Acid Catalysis Brønsted Acid Catalysis X

  13. DETERMINATION OF ANTHRANILIC ACID BY POTENTIOMETRIC TITRATION

    Microsoft Academic Search

    Dana Moja; I. Badea

    Cerium (IV) sulfate solution in sulfuric acid was used for the determination of o-aminobenzoic acid in sulfuric acid solution by potentiometric titration. The optima working conditions were set up for the quantitative determination of o-aminobenzoic acid. The method is simple, rapid and reliable. The effects of the acidity of the reaction medium and of the titrant concentration have been investigated.

  14. Bile acids--what's new.

    PubMed

    Leveille-Webster, C

    1997-02-01

    Increases in serum and tissue bile acid concentrations occur in hepatobiliary disease. In feline patients, the determination of serum bile acid concentrations is a sensitive and specific test for the diagnosis of acquired hepatobiliary disease and congenital portosystemic shunts. Because it is known that high concentrations of bile acids are cytotoxic, it has been speculated that they contribute to the pathological progression of hepatobiliary disorders. Recent evidence suggests the oral administration of the relatively nontoxic bile acid, ursodeoxycholate, can replace more hydrophobic hepatotoxic bile acids in the circulating pool and by doing so ameliorate the harmful effects of the latter. In addition, ursodeoxycholate has choleretic and immunomodulatory actions which may be of benefit in hepatobiliary disorder. PMID:9057484

  15. Thermolysis of carboxylic acid salts

    SciTech Connect

    Khlestkin, R.N.; Khlestkina, V.L.; Usanov, N.G.; Gareev, V.M.

    1982-07-01

    The dependence of the thermal stability of carboxylic acid salts on the nature of the anion and cation of the salt was studied. It was found that the capacity for thermal decomposition by salts of aliphatic, naphthenic, aromatic and heterocyclic carboxylic acids (with the exception of alkali salts) varies in inverse proportion to the values of the pK/sub a/ of the acids and to the values of the standard heats of formation of oxides (of the metal which forms the salt) relative to a monovalent bond with oxygen. An empirical equation which permits the thermal stability of many carboxylic acid salts to be predicted is given. Recommendations are developed for evaluating the relative activity of oxide and carbonate catalysts in reactions of vapor-phase conversion of aliphatic carboxylic acids to ketones and their operating temperatures.

  16. Direct formic acid fuel cells

    NASA Astrophysics Data System (ADS)

    Rice, C.; Ha, S.; Masel, R. I.; Waszczuk, P.; Wieckowski, A.; Barnard, Tom

    The performance of formic acid fuel oxidation on a solid PEM fuel cell at 60 °C is reported. We find that formic acid is an excellent fuel for a fuel cell. A model cell, using a proprietary anode catalyst produced currents up to 134 mA/cm 2 and power outputs up to 48.8 mW/cm 2. Open circuit potentials (OCPs) are about 0.72 V. The fuel cell runs successfully over formic acid concentrations between 5 and 20 M with little crossover or degradation in performance. The anodic polarization potential of formic acid is approximately 0.1 V lower than that for methanol on a standard Pt/Ru catalyst. These results show that formic acid fuel cells are attractive alternatives for small portable fuel cell applications.

  17. Molecular Structure of Galacturonic acid

    NSDL National Science Digital Library

    2003-05-08

    Galacturonic acid is the monobasic acid resulting from oxidation of the primary alcohol group of D-galactose to carboxyl. It is widely distributed as a constituent of pectins (compounds with heterogeneous grouping of acidic structural polysaccharides, found in fruit and vegetables), many plant gums, and mucilages (gummy substances obtained from certain plants, which are used as food stabilizers). Gums tend to be used as thickening and bulking agents in pharmaceutics, and they play a less obvious part in most plants. Once swallowed, their actions are no different from those of the mucilages. D-Galacturonic acid prepared from pectin can be used to synthesize vitamin C. Native pectin is a mixture of polysaccharides, with the major component a polymer of -D-galacturonic acid. Pectin has numerous other medical and pharmaceutical uses, for example in combination with plant hemicelluloses and lignin, may be useful dietary constituents in preventing coronary heart disease, diverticular disease, ulcerative colitis, and a variety of other Western diseases.

  18. Molecular Structure of Linoleic acid

    NSDL National Science Digital Library

    2003-05-08

    Linoleic acid is a polyunsaturated fatty acid occurring widely in plant glycerides or fats. Common sources include many vegetable oils such as flax seed, safflower, soybean, peanut, and corn; some margarines; and dairy fats. It is a colorless to straw-colored liquid, insoluble in water, but soluble in alcohol and ether. Linoleic acid is easily oxidized by air and is combustible. It also appears as an aluminum salt, in the form of yellow lumps or powder, that is practically insoluble in water but soluble in oils and fixed alkalai hydroxides. Linoleic acid is essential in human nutrition and is used also for soaps, animal feeds, paints, drying protective coatings, emulsifying or smoothing and wetting agents, and in biochemical research. The conjugated form of linoleic acid or CLA has been associated with health benefits such as lowered risk of cancer and atherosclerosis. Prepared CLA is available as a supplement. However, foods high in CLA content could be used.

  19. Atmospheric dust and acid rain

    SciTech Connect

    Hedin, L.O.; Likens, G.E.

    1996-12-01

    Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid rain and atmospheric dust? Suggestions range from the improbable to the feasible. One reasonable suggestion is to reduce emissions of acidic pollutants to levels that can be buffered by natural quantities of basic compounds in the atmosphere; such a goal would mean continued reductions in sulfur dioxide and nitrogen oxides, perhaps even greater than those prescribed in the 1990 Amendments to the Clean Air Act in the U.S. 5 figs.

  20. Synthesis of higher monocarboxylic acids

    SciTech Connect

    Taikov, B.F.; Novakovskii, E.M.; Zhelkovskaya, V.P.; Shadrova, V.N.; Shcherbik, P.K.

    1981-01-01

    Brown-coal and peat waxes contain higher monocarboxylic acids, alcohols and esters of them as their main components. In view of this, considerable interest is presented by the preparation of individual compounds among those mentioned above, which is particularly important in the study of the composition and development of the optimum variants of the chemical processing of the waxes. In laboratory practice, to obtain higher monocarboxylic acids use is generally made of electrosynthesis according to Kolbe which permits unbranched higher aliphatic acids with given lengths of the hydrocarbon chain to be obtained. The aim of the present work was to synthesize higher monocarboxylic acids: arachidic, behenic, lignoceric, pentacosanoic, erotic, heptacosanoic, montanic, nonacosanoic, melissic, dotriacontanoic and tetratriacontanoic, which are present in waxes. Characteristics of synthesized acids are tabulated. 20 refs.

  1. 40 CFR 721.10512 - Fatty acid maleic acid amides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 2014-07-01 2014-07-01 false Fatty acid maleic acid amides (generic). 721.10512 Section 721.10512...for Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical...

  2. 40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues. 180.550 Section... Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid];...

  3. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...

  4. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...

  5. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...

  6. 40 CFR 721.10512 - Fatty acid maleic acid amides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 2013-07-01 2013-07-01 false Fatty acid maleic acid amides (generic). 721.10512 Section 721.10512...for Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical...

  7. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...

  8. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...

  9. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ...FRL-9396-9] Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption AGENCY: Environmental Protection...for residues of styrene, copolymers with acrylic acid and/or methacrylic acid, with none and/or...

  10. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...

  11. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...

  12. 40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues. 180.550 Section... Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid];...

  13. 40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues. 180.550 Section... Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid];...

  14. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...

  15. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...

  16. Nonprotein Amino Acids from Spark Discharges and Their Comparison with the Murchison Meteorite Amino Acids

    PubMed Central

    Wolman, Yecheskel; Haverland, William J.; Miller, Stanley L.

    1972-01-01

    All the nonprotein amino acids found in the Murchison meteorite are products of the action of electric discharge on a mixture of methane, nitrogen, and water with traces of ammonia. These amino acids include ?-amino-n-butyric acid, ?-aminoisobutyric acid, norvaline, isovaline, pipecolic acid, ?-alanine, ?-amino-n-butyric acid, ?-aminoisobutyric acid, ?-aminobutyric acid, sarcosine, N-ethylglycine, and N-methylalanine. In addition, norleucine, alloisoleucine, N-propylglycine, N-isopropylglycine, N-methyl-?-alanine, N-ethyl-?-alanine ?,?-diaminopropionic acid, isoserine, ?,?-diaminobutyric acid, and ?-hydroxy-?-aminobutyric acid are produced by the electric discharge, but have not been found in the meteorite. PMID:16591973

  17. Caldensinic acid, a prenylated benzoic acid from Piper caldense

    Microsoft Academic Search

    Giovana C. Freitas; Rodrigo O. Saga Kitamura; João Henrique G. Lago; Maria Claudia M. Young; Elsie F. Guimarães; Massuo J. Kato

    2009-01-01

    The CH2Cl2 and MeOH extracts from leaves of Piper caldense were subjected to chromatographic separation procedures to afford the new prenylated benzoic acid, caldensinic acid (3-[(2?E,6?E,10?E)-11?-carboxy-3?,7?,15?-trimethylhexadeca-2?,6?,10?,14?-tetraenyl]-4,5-dihydroxybenzoic acid) whose structure was determined by spectral analysis, mainly NMR (1H, 13C, HSQC, HMBC) and ESI-MS. The natural compound and derivatives displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum by

  18. Alkaline cleavage of hydroxy unsaturated fatty acids. I. Ricinoleic acid and lesquerolic acid

    Microsoft Academic Search

    M. J. Diamond; R. G. Binder; T. H. Applewhite

    1965-01-01

    The effects of temperature and media on the fusion of ricinoleic and lesquerolic acid derivatives with concentrated aqueous\\u000a alkali were examined. Improved yields of?-hydroxy acids were obtained by use of excess 2-octanol. The effect of excess 2-octanol is discussed in relation to a recently\\u000a proposed reaction mechanism.

  19. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

    PubMed

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

    2012-11-01

    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ? Erie > Huron > Superior ? Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid. PMID:22722738

  20. Nucleic Acid Chaperone Activity of HIV1

    E-print Network

    Levin, Judith G.

    Nucleic Acid Chaperone Activity of HIV1 Nucleocapsid Protein: Critical Role in Reverse ............................................................................ 218 II. Structure and Nucleic Acid Binding Properties of HIV1 NC ........................................................................... 219 A. Specific and Nonspecific Nucleic Acid Binding .............................. 220 B. Structural

  1. Macromolecular Organic Acids in the Murchison Meteorite

    NASA Astrophysics Data System (ADS)

    Watson, J. S.; Sephton, M. A.; Gilmour, I.

    2005-03-01

    This study has detected bound organic acids within the Murchison meteorite organic macromolecule. Benzoic acid was the most abundant compound; other abundant compounds include C1 and C2 benzoic acids. Their origin and significance will be discussed.

  2. Acid preservation systems for food products

    SciTech Connect

    Tiberio, J. E.; Cirigiano, M. C.

    1984-10-16

    Fumaric acid is used in combination with critical amounts of acetic acid to preserve acid containing food products from microbiological spoilage in the absence of or at reduced levels of chemical preservative.

  3. Cholesterolaemic effect of palmitic acid in relation to other dietary fatty acids

    Microsoft Academic Search

    Margaret A French; Kalyana Sundram; M Thomas Clandinin

    2002-01-01

    The effect of dietary intake of high palmitic acid levels in combination with other fatty acids in normal subjects was assessed. Palmitic acid (10% of energy) was fed in conjunction with decreasing levels of linoleic acid to determine if a threshold level of linoleic acid prevented palmitic acid from being hypercholesterolaemic. Healthy subjects received each of the diet treatments for

  4. Growth temperature affects accumulation of exogenous fatty acids and fatty acid composition in Schizosaccharomyces pombe

    Microsoft Academic Search

    Virginia M. McDonough; Therese M. Roth

    2004-01-01

    The incorporation of exogenously supplied fatty acids, palmitic acid, palmitoleic acid, oleic acid and linoleic acid, was examined in the yeast Schizosaccharomyces pombe at two growth temperatures, 20 °C and 30 °C. Fatty acids supplied to S. pombe in the growth medium were found to be preferentially incorporated into the cells, becoming a dominant species. The relative increase in exogenous

  5. Phytic acid in green leaves.

    PubMed

    Hadi Alkarawi, H; Zotz, G

    2014-07-01

    Phytic acid or phytate, the free-acid form of myo-inositolhexakiphosphate, is abundant in many seeds and fruits, where it represents the major storage form of phosphorus. Although also known from other plant tissues, available reports on the occurrence of phytic acid, e.g. in leaves, have never been compiled, nor have they been critically reviewed. We found 45 published studies with information on phytic acid content in leaves. Phytic acid was almost always detected when studies specifically tried to detect it, and accounted for up to 98% of total P. However, we argue that such extreme values, which rival findings from storage organs, are dubious and probably result from measurement errors. Excluding these high values from further quantitative analysis, foliar phytic acid-P averaged 2.3 mg·g(-1) , and represented, on average, 7.6% of total P. Remarkably, the ratio of phytic acid-P to total P did not increase with total P, we even detected a negative correlation of the two variables within one species, Manihot esculenta. This enigmatic finding warrants further attention. PMID:24341824

  6. Terahertz spectrum of gallic acid

    NASA Astrophysics Data System (ADS)

    Wu, Meng; Zhao, Guozhong; Wang, Haiyan; Liang, Chengshen

    2009-11-01

    Gallic acid is natural polyphenol compound found in many green plants. More and more experiments have demonstrated that the gallic acid has comprehensive applications. In the field of medicine, the gallic acid plays an important role in antianaphylaxis, antineoplastic, antimycotic, anti-inflammatory, antivirotic, antiasthmatic and inhibiting the degradation of insulin. It also has a lot of applications in chemical industry, food industry and light industry. So it is important to study the terahertz time-domain spectroscopy of gallic acid. Terahertz time-domain spectroscopy (THz-TDS) is a new coherent spectral technology based on the femtosecond laser. In this work, the spectral characteristics of gallic acid in the range of 0.4 THz to 2.6 THz have been measured by THz-TDS. We obtained its absorption and refraction spectra at room temperature. The vibration absorption spectrum of the single molecule between 0.4 THz and 2.6 THz is simulated based on the Density Functional Theory (DFT). It is found that the gallic acid has the spectral response to THz wave in this frequency range. The results show the abnormal dispersion at 1.51 THz and 2.05 THz. These results can be used in the qualitative analysis of gallic acid and the medicine and food inspection.

  7. Ion chromatographic determination of acidity.

    PubMed

    De Borba, B M; Kinchin, C M; Sherman, D; Cook, T K; Dasgupta, P K; Srinivasan, K; Pohl, C A

    2000-01-01

    The practice of determining acid concentrations by titrations has remained unchanged for more than a century. We introduce a new approach to the determination of acid concentrations based on cation exchange chromatography. We demonstrate the ability of sulfonated styrene-divinylbenzene based stationary phases to separate the hydrogen ion from other monovalent cations. The eluent is a dilute solution of a neutral salt, sometimes containing a small concentration of the corresponding acid, e.g., sodium ethanesulfonate, pH adjusted with ethanesulfonic acid. The high equivalent conductance (approximately 350 S.cm2/equiv) of H+ and relatively low eluent concentration allows sensitive conductometric detection of H+, down to the 50 microM level under favorable conditions. The conductometric response to H+ can be linear over a wide range of H+ concentrations, from sub-millimolar to several molar concentrations. The system allows the rapid quantitation of strong acids; weak acids can also be determined depending on pKa and injected concentration. The determinations of several strong and weak acids are presented along with factors that govern their chromatographic analysis. PMID:10655640

  8. Anticonvulsant activity of cyclopentano amino acids

    Microsoft Academic Search

    Robert Zand; Ivan Izquierdo

    1980-01-01

    The hypothesis that certain amino acid analogues possessing a five-membered ring structure or amino acid analogues that can be viewed as fragments derived from such a ring would have anticonvulsant activity was proposed and tested. The compounds 1-aminocyclopentane carboxylic acid, 1-amino-3-methylcyclopentane carboxylic acid, 3-aminotetrahydrothiophene carboxylic acid, and a-aminoisobutyric acid were found to protect rats against seizures in the maximal electroshock

  9. Nucleic acid arrays and methods of synthesis

    SciTech Connect

    Sabanayagam, Chandran R. (Allston, MA); Sano, Takeshi (Needham, MA); Misasi, John (Syracuse, NY); Hatch, Anson (Seattle, WA); Cantor, Charles (Del Mar, CA)

    2001-01-01

    The present invention generally relates to high density nucleic acid arrays and methods of synthesizing nucleic acid sequences on a solid surface. Specifically, the present invention contemplates the use of stabilized nucleic acid primer sequences immobilized on solid surfaces, and circular nucleic acid sequence templates combined with the use of isothermal rolling circle amplification to thereby increase nucleic acid sequence concentrations in a sample or on an array of nucleic acid sequences.

  10. Extraction of uranium values from phosphoric acid

    Microsoft Academic Search

    T. Largman; S. Sifniades; A. A. Tunick

    1982-01-01

    Aqueous phosphoric acid solutions containing uranium values are contacted with an organic solution of a mixture of organophosphorus compounds produced from a carboxylic acid and pcl3 in the presence of water or from corresponding acid halides or anhydrides and phosphorous acid to extract the uranium values. The organophorus compounds generally include an alkane-1,1,2triphosphonic acid or a 1-hydroxy-1,1-alkanediphosphonic acid or both,

  11. Oxidation of Benzaldehyde to Benzoic Acid

    Microsoft Academic Search

    Hongyan Yan; Chunsheng Liu; Genxiang Luo

    2005-01-01

    Benzaldehyde was oxidized to benzoic acid using Na2WO4·2H2O as a catalyst. Different factors, such as different acidic additives, the reaction time, the amount of catalyst, and hydrogen peroxide dosage, on the isolated yield of benzoic acid were investigated. The effects of surfactants on yield of benzoic acid were also discussed in the acid-free system. The results indicated that both acidic

  12. Oligomer distribution in concentrated lactic acid solutions

    Microsoft Academic Search

    Dung T. Vu; Aspi K. Kolah; Navinchandra S. Asthana; Lars Peereboom; Carl T. Lira; Dennis J. Miller

    2005-01-01

    Lactic acid (2-hydroxypropanoic acid) is a significant platform chemical for the biorenewable economy. Concentrated aqueous solutions of lactic acid (>30wt.%) contain a distribution of oligomers that arise via intermolecular esterification. As a result, the titratable acidity changes non-linearly with acid concentration. In this work, the oligomer distribution of lactic acid is characterized using GC, GC\\/MS, and HPLC to extend existing

  13. Naphthenic acid corrosion literature survey

    SciTech Connect

    Babaian-Kibala, E. [Nalco/Exxon Energy Chemicals, Sugar Land, TX (United States); Nugent, M.J. [Tosco Refining Co., Linden, NJ (United States)

    1999-11-01

    Naphthenic acid corrosion is a growing concern for refineries processing crudes containing high levels of naphthenic acid. Due to this concern initiatives in place to better understand the mechanism of corrosion for mitigating the corrosion. During the 1996 Fall Corrosion Group, organized existing literature relevant to the literature search. Committee Week, NACE International many refineries have and evaluate methods T-8 Refining Industry a task group, T-8-22, to perform a review and compilation of naphthenic acid corrosion. This paper provides a summary of the literature research.

  14. Be an acid rain detective

    SciTech Connect

    Atwill, L.

    1982-07-01

    Acid rain is discussed in a question and answer format. The article is aimed at educating sport fishermen on the subject, and also to encourage them to write their congressmen, senators, and the President about the acid rain problem. The article also announces the availability of an acid rain test kit available through the magazine, ''Sports Afield.'' The kit consists of pH-test paper that turns different shades of pink and blue according to the pH of the water tested. The color of the test paper is then compared to a color chart furnished in the kit and an approximate pH can be determined.

  15. Drilling fluids containing amps, acrylic acid, itaconic acid polymer

    SciTech Connect

    Bardoliwalla, D.F.

    1987-10-13

    This patent describes an aqueous drilling fluid having present in an amount sufficient to reduce fluid loss of the drilling fluid, at least one polymer of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component, there being from 100% to about 80% by weight of acrylic acid and from 0% by weight to about 20% by weight of itaconic acid in the second component. The polymer has a weight average molecular weight of between about 50,000 to about 1,000,000 being in its free acid or partially or completely neutralized form and being at least water dispersible. A method is described of drilling a well into a subterranean formation in which an aqueous drilling fluid is circulated into the well. The step of circulating the drilling fluid contains in an amount sufficient to reduce fluid loss of the drilling fluid, at least one polymer of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component. There is from 100% to about 80% by weight of acrylic acid and from 0% by weight to about 20% by weight of itaconic acid in the second component. The polymer has weight average molecular weight of between about 50,000 to about 1,000,000 in its free acid or partially or completely neutralized form and is at least water dispersible.

  16. Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

    Microsoft Academic Search

    J. A. Jaén; L. González; A. Vargas; G. Olave

    2003-01-01

    The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer\\u000a spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to\\u000a these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction\\u000a was followed up to 3 months. Results indicated

  17. Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

    SciTech Connect

    Schick, P.K.; Webster, P.

    1987-05-01

    Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with (/sup 14/C)-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of (/sup 14/C)-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of (/sup 14/C)-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of (/sup 14/C)-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA.

  18. Enhanced acid tolerance of Rhizopus oryzae during fumaric acid production.

    PubMed

    Liu, Ying; Lv, Chunwei; Xu, Qing; Li, Shuang; Huang, He; Ouyang, Pingkai

    2015-02-01

    Ensuring a suitable pH in the culture broth is a major problem in microorganism-assisted industrial fermentation of organic acids. To address this issue, we investigated the physiological changes in Rhizopus oryzae at different extracellular pH levels and attempted to solve the issue of cell shortage under low pH conditions. We compared various parameters, such as membrane fatty acids' composition, intracellular pH, and adenosine triphosphate (ATP) concentration. It was found that the shortage of intracellular ATP might be the main reason for the low rate of fumaric acid production by R. oryzae under low pH conditions. When 1 g/l citrate was added to the culture medium at pH 3.0, the intracellular ATP concentration increased from 0.4 to 0.7 µmol/mg, and the fumaric acid titer was enhanced by 63% compared with the control (pH 3.0 without citrate addition). The final fumaric acid concentration at pH 3.0 reached 21.9 g/l after 96 h of fermentation. This strategy is simple and feasible for industrial fumaric acid production under low pH conditions. PMID:25190324

  19. GHB - Gamma-Hydroxybutyric Acid

    MedlinePLUS

    ... Ribbon Week DEA Red Ribbon Week Patch Program GHB - Gamma-Hydroxybutyric Acid Last Updated: Monday, August 4, ... in water, juice, or alcohol. In liquid form, GHB is clear and colorless and slightly salty in ...

  20. EXPOSURE MODELING OF ACID AEROSOLS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) is conducting an intensive characterization and human exposure monitoring program of acid species and related air pollutants in an urban environment. he EPA's Atmospheric Research and Exposure Assessment Laboratory (AREAL) in coopera...

  1. Antibiofilm Properties of Acetic Acid

    PubMed Central

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homøe, Preben; Høiby, Niels; Givskov, Michael; Kirketerp-Møller, Klaus

    2015-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms. PMID:26155378

  2. Making cents of acid recovery

    SciTech Connect

    Ondrey, G.; Shanley, A.

    1993-04-01

    Acid recovery may be expensive, but rising transportation and landfill costs may soon make it the only alternative. Traditionally, acids used in processes from titanium dioxide production to gasoline alkylation and metal pickling were neutralized and discharged into waterways or injected into deep wells. Today, however, discharge permits are being phased out in many countries, and deep well injection is coming under closer scrutiny. An even cheaper option was selling spent acid to fertilizer producers, who used it to dissolve phosphate ores. Health concerns, a depressed fertilizer market and tightening disposal regulations for gypsum byproduct have dried up this option. The paper discusses the processes and costs involved in spent acid regeneration, gypsum-free gas treatments, and problems with explosive contaminants.

  3. Dried Acid Mine Drainage Residuals

    USGS Multimedia Gallery

    Dried acid mine drainage residuals that are formed during treatment of the drainage.  The USGS has pioneered a new use for these residuals that are currently a disposal challenge, using them to filter phosphorus from agricultural and municipal wastewaters....

  4. Molecular Structure of Retinoic acid

    NSDL National Science Digital Library

    2004-11-11

    Retinoic acid is a yellow to light-orange crystalline powder, that is insoluble in water and slightly soluble in alcohol. Retinoic acid is a natural metabolite of vitamin A which participates in many of the known functions of vitamin A and may be the active agent in tetragenesis (still under investigation). Retinoic acid is used to improve the appearance and texture of the skin. It is also used in the treatment of certain skin diseases such as acne, psoriasis, diarier's disease and ichthyosis. Mild side-effects to the gel, primarily skin irritation, are common. Common side-effects associated with the oral formulation are: headache, dry skin, peeling skin, alopecia and high blood lipids. Retinoic acid is also very potent in promoting growth and controlling differentiation and maintenance of epithelial tissues in vitamin A deficient animals.

  5. Molecular Structure of Abscisic acid

    NSDL National Science Digital Library

    2004-11-09

    Abscisic acid (ABA) was first identified and characterized by Frederick Addicott in 1963. ABA is a naturally occurring compound in plants synthesized partially in the chloroplasts. It is a phytohormone that plays an important role in regulating transpiration, stress responses, germination of seeds and embryogenesis in plants. Abscisic acid influences most aspects of plant growth and development to some level, in part due to interactions with other phytohormones. Abscisic acid also promotes abscission of leaves and fruits, and for this reason the name abscisic is given. This plant hormone is the key factor in the adaptation of the plant to environmental stresses such as salinity, drought or water loss, and freezing temperatures. Abscisic acid promotes dormancy and helps the plant tolerate stressful conditions by suspending primary and secondary growth.

  6. Low acid producing solid propellants

    NASA Technical Reports Server (NTRS)

    Bennett, Robert R.

    1995-01-01

    The potential environmental effects of the exhaust products of conventional rocket propellants have been assessed by various groups. Areas of concern have included stratospheric ozone, acid rain, toxicity, air quality and global warming. Some of the studies which have been performed on this subject have concluded that while the impacts of rocket use are extremely small, there are propellant development options which have the potential to reduce those impacts even further. This paper discusses the various solid propellant options which have been proposed as being more environmentally benign than current systems by reducing HCI emissions. These options include acid neutralized, acid scavenged, and nonchlorine propellants. An assessment of the acid reducing potential and the viability of each of these options is made, based on current information. Such an assessment is needed in order to judge whether the potential improvements justify the expenditures of developing the new propellant systems.

  7. Controlling acid rain : policy issues

    E-print Network

    Fay, James A.

    1983-01-01

    The policy and regulatory ramifications of U.S. acid rain control programs are examined; particularly, the alternative of a receptor-oriented strategy as constrasted to emission-oriented proposals (e.g., the Mitchell bill) ...

  8. Nitrate and Prussic Acid Poisoning 

    E-print Network

    Stichler, Charles; Reagor, John C.

    2001-09-05

    Nitrate and prussic acid poisoning in cattle are noninfectious conditions that can kill livestock. This publication explains the causes and symptoms of these conditions as well as preventive measures and sampling and testing steps....

  9. Abiotic synthesis of fatty acids

    NASA Technical Reports Server (NTRS)

    Leach, W. W.; Nooner, D. W.; Oro, J.

    1978-01-01

    The formation of fatty acids by Fischer-Tropsch-type synthesis was investigated with ferric oxide, ammonium carbonate, potassium carbonate, powdered Pueblito de Allende carbonaceous chondrite, and filings from the Canyon Diablo meteorite used as catalysts. Products were separated and identified by gas chromatography and mass spectrometry. Iron oxide, Pueblito de Allende chondrite, and Canyon Diablo filings in an oxidized catalyst form yielded no fatty acids. Canyon Diablo filings heated overnight at 500 C while undergoing slow purging by deuterium produced fatty acids only when potassium carbonate was admixed; potassium carbonate alone also produced these compounds. The active catalytic combinations gave relatively high yields of aliphatic and aromatic hydrocarbons; substantial amounts of n-alkenes were almost invariably observed when fatty acids were produced; the latter were in the range C6 to C18, with maximum yield in C9 or 10.

  10. Gamma Hydroxybutyric Acid (GHB) Intoxication

    Microsoft Academic Search

    Phillip E. Mason; William P. Kerns II

    2002-01-01

    Gamma-aminobutyric acid (GABA) was discovered as the predominant inhibitory central nervous sys- tem (CNS) neurotransmitter in 1956. This prompted a search for a GABA analog that would cross the blood-brain barrier for possible therapeutic use. During this search, gamma-hydroxybutyric acid (GHB) was found in the brain and subsequently synthesized in the laboratory in 1964. 1,2 Since its discovery, GHB has

  11. Amino Acids and the Mitochondria

    Microsoft Academic Search

    Nicola King

    \\u000a This chapter describes some of the important physiological functions of amino acids in the mitochondria and the alterations\\u000a caused by specific pathologies. To some extent all of the featured items are dependent upon the movement of amino acids across\\u000a the highly selective permeability barrier that is the inner mitochondrial membrane. The performance of this transport by specific\\u000a carriers is the

  12. Molecular Structure of Glucuronic acid

    NSDL National Science Digital Library

    2003-05-08

    Glucuronic acid is a substance derived from uronic acid, and is found in both plants and animals, usually in combination with phenols or alcohols. It is primarily used in detoxifying drugs and toxins to ensure easy elimination from the body. This substance is soluble in water and alcohol and has a melting point of 165 degrees Celsius. It exhibits mutarotation in the crystal form or its specific rotation of light changes depending on the way the crystals were prepared.

  13. Folic acid and preconceptional care

    Microsoft Academic Search

    Nancy H Levine; Katherine Lyon Daniel; Joe Mulinare

    2001-01-01

    If all women capable of becoming pregnant consumed 400 ?g (0.4 mg) of the B vitamin folic acid daily before conception and during the first trimester, the annual number of neural-tube birth defect (NTD)–affected pregnancies in this country could be reduced by 50% to 70%. Despite this important relationship, most women are not aware that folic acid prevents NTDs, and

  14. Factors controlling naphthenic acid corrosion

    SciTech Connect

    Turnbull, A. [National Physical Lab., Teddington (United Kingdom); Slavcheva, E. [Bulgarian Academy of Sciences, Sofia (Bulgaria); Shone, B. [Ty Isa, Nr Mold (United Kingdom)

    1998-11-01

    A laboratory study was conducted to elucidate the influence of chemical and physical parameters on corrosion of type 1018 carbon steel (CS, UNS G10180) and 5% Cr-0.5% Mo steel in oils containing naphthenic acids (NAs) for application to crude oil refinery systems. Effects of test duration, temperature, and acid concentration were assessed for a range of single acids of varying carbon numbers and for NA mixtures in mineral oil (MO) and in heavy vacuum gas oil (HGVO). In addition, a limited study of the effect of hydrogen sulfide (H{sub 2}S) addition to the acid-oil mixture was conducted. Use of the total acid number (TAN) as a measure of corrosiveness of a crude oil was discredited further. For the same TAN value, molecular size and structure of the acid were shown to have an important influence. Tests conducted in HGVO showed lower corrosion rates than in MO, suggesting inhibition caused by S species in the oil or the steric hindrance of naphtheno-aromatic acids. In oil containing the mixture of NAs, the corrosion rate of type 1018 CS was lower than that for 5% Cr-0.5% Mo steel. The 0.1% H{sub 2}S that passed through the acid-oil mixtures had an inhibiting effect on corrosion. Predicting corrosiveness of a crude oil from the measurement of TAN, distribution of NA composition, and S content and form was particularly challenging. The simple tests used were informative, but further work will be required to establish a standard test method that can provide an adequate ranking of crudes.

  15. BranchedChain Amino Acids

    Microsoft Academic Search

    Miroslav Pátek

    The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine are synthesized by bacteria,\\u000a fungi, and plants, but are essential for vertebrates including humans, who must receive them from their\\u000a diet. The interest to construct overproducing industrial strains therefore stems from the need to supplement\\u000a the food or feed with these amino acids to use them in medical treatment and as

  16. Hydrothermal synthesis of amino acids

    SciTech Connect

    Marshall, W.L. (Oak Ridge National Lab., TN (United States))

    1994-05-01

    This study presents further evidence that amino acids can be synthesized rapidly in hydrothermal solutions from reactants that may have been present in primitive environments. Aqueous NH[sub 4]HCO[sub 3] solutions were reacted with C[sub 2]H[sub 2], H[sub 2], and O[sub 2] (formed in situ from CaC[sub 2], Ca, and H[sub 2]O[sub 2]) at 200-275[degrees]C over 0.2-2 h periods to synthesize several amino acids and abundant amines. These amino acid and amine producing reactions were not observed to occur below 150[degrees]C. Amino acids and amines also were synthesized at 210[degrees]C from solutions of NH[sub 4]OH, HCHO, NaCN, and H[sub 2]. When NH[sub 4]OH was replaced by NH[sub 4]HCO[sub 3], the syntheses predominantly confirmed the recent results of Hennet et al. (1992). Additionally, amino acids and amines were observed to form by reactions among NH[sub 4]OH, HCHO, and H[sub 2] at hydrothermal conditions, essentially confirming the results of Fox and Windsor (1970). Inclusion of both carbonate and O[sub 2] in these latter solutions greatly enhanced the production rate of amino acids. The amines synthesized hydrothermally could be significant if they are precursors in the amino acid syntheses either at hydrothermal or later at lower temperatures. These observations provide additional input to the current questions of synthesis, stability, and decomposition of amino acids at hydrothermal conditions, and their possible relevance to the origin of life.

  17. Molecular Structure of Oxalic acid

    NSDL National Science Digital Library

    2004-11-10

    Oxalic acid is an odorless, colorless powder or granular solid. It is used as a scouring agent in textiles for finishing, stripping, cleaning, and as a bleaching agent for stain removal. Oxalic acid is also used as a rust remover as well as a grease and wax removing agent in metal cleaning. It is also used to clean and sterilize equipment, slso as a purifying agent in the pharmaceutical industry, in the waste water treatment industry and is also used to remove calcium from water. Oxalic acid is found in many plants and in many vegetables, for example sorrel, spinach and rhubarb, usually as its calcium or potassium salts. Oxalic acid is produced commercially by nitric acid oxidation of starch. It also can be made by fusing sawdust (or other forms of cellulose) with a mixture of sodium hydroxide and potassium hydroxide. Oxalic acid may be released to the environment in tobacco smoke, automobile exhaust, rendering, in waste streams from pulp bleaching, and by photochemical oxidations of anthropogenic compounds during long range transport.

  18. Conjugated Linoleic Acid Accumulation via 10Hydroxy12-Octadecaenoic Acid during Microaerobic Transformation of Linoleic Acid by Lactobacillus acidophilus

    Microsoft Academic Search

    JUN OGAWA; KENJI MATSUMURA; SHIGENOBU KISHINO; YORIKO OMURA; SAKAYU SHIMIZU

    2001-01-01

    Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or

  19. Growth temperature affects accumulation of exogenous fatty acids and fatty acid composition in Schizosaccharomyces pombe

    Microsoft Academic Search

    Virginia M. McDonough; Therese M. Roth

    2004-01-01

    The incorporation of exogenously supplied fatty acids, palmitic acid, palmitoleic acid, oleic acid and linoleic acid, was\\u000a examined in the yeast Schizosaccharomyces pombe at two growth temperatures, 20?C and 30?C. Fatty acids supplied to S. pombe in the growth medium were found to be preferentially incorporated into the cells, becoming a dominant species. The relative\\u000a increase in exogenous fatty acids

  20. Fukiic and piscidic acid esters from the rhizome of Cimicifuga racemosa and the in vitro estrogenic activity of fukinolic acid.

    PubMed

    Kruse, S O; Löhning, A; Pauli, G F; Winterhoff, H; Nahrstedt, A

    1999-12-01

    Hydroxycinnamic acid esters of fukiic acid and piscidic acid were isolated from a 50% ethanolic extract obtained from the rhizomes of Cimicifuga racemosa (Ranunculaceae). Besides 2-E-caffeoylfukiic acid (fukinolic acid), 2-E-feruloylfukiic acid (cimicifugic acid A), 2-E-isoferuloylfukiic acid (cimicifugic acid B), 2-E-feruloylpiscidic acid (cimicifugic acid E) and 2-E-isoferuloylpiscidic acid (cimicifugic acid F), free caffeic, ferulic and isoferulic acids were isolated. The estrogenic activity of fukinolic acid was shown by increased proliferation (126% at 5 x 10(-8) M) of an estrogen dependent MCF-7 cell system with reference to estradiol (120% at 10(-10) M). PMID:10630125

  1. Bile acids: regulation of apoptosis by ursodeoxycholic acid

    PubMed Central

    Amaral, Joana D.; Viana, Ricardo J. S.; Ramalho, Rita M.; Steer, Clifford J.; Rodrigues, Cecília M. P.

    2009-01-01

    Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases. PMID:19417220

  2. Biosynthesis of poly(?-glutamic acid) from l -glutamic acid, citric acid, and ammonium sulfate in Bacillus subtilis IFO3335

    Microsoft Academic Search

    Masao Kunioka; Atsuo Goto

    1994-01-01

    Poly(?-glutamic acid) (PGA) production in Bacillus subtilis IFO3335 was studied. When l-glutamic acid, citric acid, and ammonium sulfate were used as carbon and nitrogen sources, a large amount of PGA without a by-product such as a polysaccharide was produced. The time courses of cell growth, PGA, glutamic acid, and citric acid concentrations during cultivation were investigated. It was found that

  3. Amyloid-Associated Nucleic Acid Hybridisation

    Microsoft Academic Search

    Sebastian Braun; Christine Humphreys; Elizabeth Fraser; Andrea Brancale; Matthias Bochtler; Trevor C. Dale

    2011-01-01

    Nucleic acids promote amyloid formation in diseases including Alzheimer's and Creutzfeldt-Jakob disease. However, it remains unclear whether the close interactions between amyloid and nucleic acid allow nucleic acid secondary structure to play a role in modulating amyloid structure and function. Here we have used a simplified system of short basic peptides with alternating hydrophobic and hydrophilic amino acid residues to

  4. Acid sorption regeneration process using carbon dioxide

    DOEpatents

    King, C. Judson (Kensington, CA); Husson, Scott M. (Anderson, SC)

    2001-01-01

    Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent in the presence of carbon dioxide under pressure. The acids are freed from the sorbent phase by a suitable regeneration method, one of which is treating them with an organic alkylamine solution thus forming an alkylamine-carboxylic acid complex which thermally decomposes to the desired carboxylic acid and the alkylamine.

  5. Fatty Acids Homeostasis; the search for

    E-print Network

    Knyazev, Andrew

    Fatty Acids Homeostasis; the search for the key regulatory factors. --Andrew Knyazev, Math CUStargardt''ss--like macular degenerationlike macular degeneration FA metabolic proteins in diseases #12;FA Homeostasis of the Fatty Acids moleculesFatty Acids molecules !! The mechanism of Fatty Acid homeostasis is not understood

  6. 21 CFR 184.1091 - Succinic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4 H6 O4 , CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical...

  7. 21 CFR 184.1091 - Succinic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4 H6 O4 , CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical...

  8. 21 CFR 189.155 - Monochloroacetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...

  9. 21 CFR 189.155 - Monochloroacetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...

  10. 21 CFR 189.155 - Monochloroacetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...

  11. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2009-04-01 true Aconitic acid. 184.1007 Section 184.1007 Food and Drugs...Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid (C6...

  12. 21 CFR 184.1007 - Aconitic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Aconitic acid. 184.1007 Section 184.1007 Food and Drugs...Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid (C6...

  13. 21 CFR 189.155 - Monochloroacetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...

  14. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 2011-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and Drugs...Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7 H6...

  15. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2009-04-01 true Benzoic acid. 184.1021 Section 184.1021 Food and Drugs...Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7 H6...

  16. 21 CFR 189.155 - Monochloroacetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...

  17. ACIDIC BIOPOLYMERS AS DISPERSANTS FOR CERAMIC PROCESSING

    E-print Network

    Aksay, Ilhan A.

    123 ACIDIC BIOPOLYMERS AS DISPERSANTS FOR CERAMIC PROCESSING N. PELLERIN,* J. T. STALEY,* T. REN, University of Washington, Seattle, WA 98195 Some acidic biopolymers serve as dispersantsfor colloidal was reduced by partial acid hydrolysis. Low molecular weight polymers rich in guluronic acid proved

  18. Agronomy Facts 3 Soil Acidity and Aglime

    E-print Network

    Kaye, Jason P.

    Agronomy Facts 3 Soil Acidity and Aglime Summary · Soil pH indicates the acidic level of a soil. A pH less than 7.0 indicates an acid soil. · Soil acidification is a natural process that is increased of soil acidity (low soil pH) can reduce root growth, reduce nutrient availability, and affect crop

  19. Fatty acids for myocardial imaging.

    PubMed

    Corbett, J R

    1999-07-01

    Radioiodinated free fatty acids are tracers that can be used to assess both myocardial perfusion and metabolism. There have been several fatty acids and structurally modified fatty acids studied since Evans' initial report of radiolabeled I-123 oleic acid in 1965. The radiolabeling of a phenyl group added to the long chain fatty acids in the omega-terminal position opposite the carboxyl terminal group prevents nonspecific deiodination and the rapid release of free iodine as the tracer undergoes beta-oxidation. The additional inclusion of a methyl or dimethyl group to the chain slows oxidation resulting in prolonged myocardial retention. The longer retention of the radiolabel permits longer image acquisitions more compatible with single photon emission computed tomography (SPECT) imaging, especially with single-detector imaging systems. Several protocols have been implemented using these compounds, particularly 15-(para-iodophenyl)-3-R,S-methyl pentadecanoic BMIPP, to detect abnormal fatty acid metabolism in ischemic heart disease as well as in nonischemic and hypertrophic cardiomyopathies. Successful management of patients with ischemic cardiomyopathies depends on the accurate identification of hibernating myocardium. The studies covered in this review suggest that both IPPA and BMIPP, especially when combined with markers of myocardial perfusion, may be excellent tracers of viable and potentially functional myocardium. Future studies with larger numbers of patients are needed to confirm the results of these studies and to compare their efficacy with that of other available imaging modalities. Cost and distribution issues will have to be resolved for these metabolic tracers to compete in the commercial marketplace. Otherwise they will likely be available only on a limited basis for research use. As progress is made with these issues and with the development of newer imaging systems, the use of radioiodinated and fluorinated fatty acids is likely to be increasingly attractive. PMID:10433339

  20. History of retinoic acid receptors.

    PubMed

    Benbrook, Doris M; Chambon, Pierre; Rochette-Egly, Cécile; Asson-Batres, Mary Ann

    2014-01-01

    The discovery of retinoic acid receptors arose from research into how vitamins are essential for life. Early studies indicated that Vitamin A was metabolized into an active factor, retinoic acid (RA), which regulates RNA and protein expression in cells. Each step forward in our understanding of retinoic acid in human health was accomplished by the development and application of new technologies. Development cDNA cloning techniques and discovery of nuclear receptors for steroid hormones provided the basis for identification of two classes of retinoic acid receptors, RARs and RXRs, each of which has three isoforms, ?, ? and ?. DNA manipulation and crystallographic studies revealed that the receptors contain discrete functional domains responsible for binding to DNA, ligands and cofactors. Ligand binding was shown to induce conformational changes in the receptors that cause release of corepressors and recruitment of coactivators to create functional complexes that are bound to consensus promoter DNA sequences called retinoic acid response elements (RAREs) and that cause opening of chromatin and transcription of adjacent genes. Homologous recombination technology allowed the development of mice lacking expression of retinoic acid receptors, individually or in various combinations, which demonstrated that the receptors exhibit vital, but redundant, functions in fetal development and in vision, reproduction, and other functions required for maintenance of adult life. More recent advancements in sequencing and proteomic technologies reveal the complexity of retinoic acid receptor involvement in cellular function through regulation of gene expression and kinase activity. Future directions will require systems biology approaches to decipher how these integrated networks affect human stem cells, health, and disease. PMID:24962878

  1. INTRODUCTION ACID-BASE EQUILIBRIAACID-BASE EQUILIBRIA

    E-print Network

    Hardy, Darel

    INTRODUCTION ACID-BASE EQUILIBRIAACID-BASE EQUILIBRIA What are acids and bases? Svante Arrhenius noticed that acids release hy- drogen ions in solution. He classified acids and bases in this way: acids in water to accept a proton. Acids that break up completely in water; these are strong acids. Acids that do

  2. Acid Rain: What It Is -- How You Can Help!

    ERIC Educational Resources Information Center

    National Wildlife Federation, Washington, DC.

    This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…

  3. Selective Catalysis of Lactic Acid to Produce Commodity Chemicals

    Microsoft Academic Search

    Yongxian Fan; Chunhui Zhou; Xiaohong Zhu

    2009-01-01

    Owning to its biobased organic acid, low cost and multiple reactive functionalities as it contains both one carboxylic acid group and hydroxyl group, lactic acid has been described as a commodity chemical sleeping giant. In this review, the conversion of lactic acid to other important commodity chemicals, such as, poly L?lactic acid, acrylic acid, 2, 3?pentanedione, pyruvic acid, propanoic acid,

  4. Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid

    USGS Publications Warehouse

    Sierra-Alvarez, R.; Yenal, U.; Feld, J.A.; Kopplin, M.; Gandolfi, A.J.; Garbarino, J.R.

    2006-01-01

    Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively. ?? 2006 American Chemical Society.

  5. Naphthenic acids and surrogate naphthenic acids in methanogenic microcosms.

    PubMed

    Holowenko, F M; Mackinnon, M D; Fedorak, P M

    2001-08-01

    Naphthenic acids (NAs) are a complex mixture of naturally occurring acyclic and cyclic aliphatic carboxylic acids in petroleum. In the Athabasca oil sands. NAs have been identified as the largest component of dissolved organic matter in the tailings waters from oils sands extraction processes. They are the major contributor to the acute toxicity of the fine tailings wastewaters at the oil sands extraction plants in northeastern Alberta, Canada. In this study, three sources of NAs were studied, including commercially available NAs, those extracted from oil sands process-affected waters, and individual naphthenic-like surrogate compounds. Analysis by gas chromatography-mass spectrometry demonstrated differences between the commercial and extracted NAs. The NAs derived from the process-affected waters showed a short-term inhibition of methanogenesis from H2 or acetate, but with time the populations resumed methane production. It has been postulated that microbial metabolism of the carboxylated side chains of NAs would lead to methane production. The two NA mixtures failed to stimulate methanogenesis in microcosms that contained either oil sands fine tailings or domestic sewage sludge. However, in microcosms with sewage sludge, methanogenesis was stimulated by some surrogate NAs including 3-cyclohexylpropanoic acid at 400-800 mg/L, 5-cyclohexylpentanoic acid at 200 mg/L or 6-phenylhexanoic acid at 200 and 400 mg/L. When added at 200 mg/L to methanogenic microcosms containing fine tailings, 3-cyclohexylpropanoic and 4-cyclohexylbutanoic acids produced methane yields that suggested mineralization of the side chain and the ring. PMID:11456157

  6. Arterial Blood Carbonic Acid Inversely Determines Lactic and Organic Acids

    PubMed Central

    Aiken, Christopher Geoffrey Alexander

    2013-01-01

    Objective: To establish that arterial blood carbonic acid varies inversely with lactic acid in accordance with bicarbonate exchanging for lactate across cell membranes through the anion exchange mechanism to maintain the Gibbs-Donnan equilibrium. Study Design: Over 5 years, lactate was measured on all blood gases taken from neonatal admissions, as well as organic acid whenever electrolytes were required. Results: Arterial blood gases from 63 infants given high calcium TPN were analyzed. Twenty two needed continuous positive airways pressure (CPAP) only and 31 intermittent positive pressure ventilation (IPPV) and surfactant followed by CPAP to treat respiratory distress syndrome in 51 and meconium aspiration syndrome in 2. All survived and were free of infection. Excluded gases were those with high and falling lactate soon after delivery representing perinatal asphyxia, and those on dexamethasone. Strong inverse relations between carbonic and lactic acids were found at all gestational ages and, independent of glomerular filtration, between carbonic and organic acids. Lactate (mmol/L) = 62.53 X PCO2 -0.96(mmHg) r2 0.315, n 1232, p <0.001. Sixty divided by PCO2 is a convenient measure of physiological lactate at any given PCO2. In the first week, 9.13 ± 2.57% of arterial gases from infants on IPPV had lactates above 120/PCO2, significantly more than 4.74 ± 2.73% on CPAP (p<0.05) and 2.47 ± 2.39% on no support. Conclusion: Changes in arterial blood carbonic acid cause immediate inverse changes in lactic acid, because their anions interchange across cell membranes according to the Gibbs –Donnan equilibrium. Increasing PCO2 from 40 to 120 mmHg decreased lactate from 1.5 mmol/L to 0.5 mmol/L, so that the sum of carbonic and lactic acids increased from 2.72 mmol/L to only 4.17 mmol/L. This helps explain the neuroprotective effect of hypercapnoea and highlights the importance of avoiding any degree of hypocapnoea in infants on IPPV. PMID:24392387

  7. Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

    NASA Astrophysics Data System (ADS)

    Jaén, J. A.; González, L.; Vargas, A.; Olave, G.

    2003-06-01

    The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

  8. Acidic properties of aqueous phosphoric acid solutions: a microscopic view.

    PubMed

    Harsányi, I; Pusztai, L; Jóvári, P; Beuneu, B

    2013-11-13

    We report on new neutron and x-ray diffraction data on D2O:D3PO4 solutions at two concentrations, 1:1 and 3:1. The experimental datasets were modelled simultaneously by the reverse Monte Carlo (RMC) method. From the resulting models, partial radial distribution functions (prdf) and coordination numbers were obtained. The acidity was found to decrease with increasing D3PO4 concentration. The ratio of dissociated acidic protons was estimated by dedicated simulation runs using average coordination number constraints. It was found that in the saturated solution the ratio of dissociated protons cannot exceed 20%. PMID:24140599

  9. New developments in synthetic fatty acids

    Microsoft Academic Search

    Norman O. V. Sonntag

    1969-01-01

    New developments in synthetic fatty acids have occurred in the last few years in Russia, Japan, the United States and Canada.\\u000a In 1959 Russia decided to replace 40% of natural fatty acids in soaps with synthetic fatty acids. In 1966, 548 million pounds\\u000a of C5–C30 synthetic fatty acids were produced including 288 million pounds of C10–C20 fatty acids. Forty million

  10. Identifying a base in a nucleic acid

    SciTech Connect

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2005-02-08

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  11. Phenol biosynthesis in higher plants. Gallic acid

    PubMed Central

    Dewick, P. M.; Haslam, E.

    1969-01-01

    The biosynthesis of gallic acid in a number of higher plants was investigated by using l-[U-14C]phenylalanine, (?)-[G-14C]shikimic acid, d-[1-14C]glucose and d-[6-14C]glucose as tracers. The results are compared with those obtained similarly for caffeic acid and are interpreted in terms of the dehydrogenation of 5-dehydroshikimic acid as a normal route of metabolism for gallic acid. PMID:5807212

  12. Inhibitors of Fatty Acid Synthesis and Elongation

    NSDL National Science Digital Library

    Fatty acid synthesis and fatty acid elongation are two parts of a critically important pathway in plants. The endproducts are essential components of cell membranes, waxes, and suberin. Two chemical families of herbicide (groups that share similar chemical structures) inhibit fatty acid synthesis, while fatty acid elongation is inhibited by two other families. This lesson will provide an overview of fatty acid synthesis and elongation, and explain where herbicides inhibit the pathway. Mechanisms of resistance to these herbicides will be described.

  13. Preparation of some amino phosphonic acids 

    E-print Network

    Chambers, James Richard

    1958-01-01

    chloride and sodium hydroxide, rapid stirring was continued for another 30 minutes. This solution was then made acidic to congo red with 6 N hydro? chloric acid, extracted with 13 ml. of diethyl ether to remove unreacted benzoyl chloride and any benzoic... acid is insoluble in ethyl alcohol but its hydrochloride is soluble; therefore, the free acid can be obtained easily by dissolving the hydro? chloride in ethyl alcohol and precipitating the free acid (III) with butene oxide, A 0 + CH...

  14. Gelled acidic well treating composition and process

    SciTech Connect

    Swanson, B.L.

    1981-01-13

    Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations comprising water , a water-dispersible polymer selected from cellulose ethers and polymers of acrylamides, an acid, an aldehyde, and a phenolic compound capable of causing gelation of an aqueous dispersion of the polymer, acid, aldehyde, and phenolic compound are provided. In another embodiment, guar gum, polyvinylpyrrolidone and biopolysaccharides can also be used as the polymeric component in said compositions.

  15. Production of arachidonic acid by Mortierella fungi

    Microsoft Academic Search

    Yoshifumi Shinmen; Sakayu Shimizu; Kengo Akimoto; Hiroshi Kawashima; Hideaki Yamada

    1989-01-01

    Various Mortierella fungi were assayed for their productivity of arachidonic acid (ARA). Only strains belonging to the subgenus Mortierella accumulated detectable amounts of ARA together with dihomo-?-linolenic acid. None of the strains belonging to the subgenus Micromucor tested accumulated these C-20 fatty acids, although they produced a C-18 fatty acid, ?-linolenic enic acid. A soil isolate, M. alpina 1S-4, was

  16. Polyunsaturated Fatty Acids in Children

    PubMed Central

    2013-01-01

    Polyunsaturated fatty acids (PUFAs) are the major components of brain and retina, and are the essential fatty acids with important physiologically active functions. Thus, PUFAs should be provided to children, and are very important in the brain growth and development for fetuses, newborn infants, and children. Omega-3 fatty acids decrease coronary artery disease and improve blood flow. PUFAs have been known to have anti-inflammatory action and improved the chronic inflammation such as auto-immune diseases or degenerative neurologic diseases. PUFAs are used for metabolic syndrome related with obesity or diabetes. However, there are several considerations related with intake of PUFAs. Obsession with the intake of unsaturated fatty acids could bring about the shortage of essential fatty acids that are crucial for our body, weaken the immune system, and increase the risk of heart disease, arrhythmia, and stroke. In this review, we discuss types, physiologic mechanism of action of PUFAs, intake of PUFAs for children, recommended intake of PUFAs, and considerations for the intake of PUFAs. PMID:24224148

  17. Amino acids and cell regulation.

    PubMed Central

    Forster, R. P.; Goldstein, L.

    1979-01-01

    Free amino play an important role in regulating cell volume in fishes. Four tissues/cells (skeletal muscle, RBC, brain, and myocardium) of the little skate, Raja erinacea, were selected for detailed study because of their special importance or unique advantage as experimental models. Three particular amino acids, beta-alanine, taurine, and sarcosine play a predominant role in all four tissues. As in higher vertebrates, amino acid uptake in skate brain, heart, and RBC is mediated via a Na+-dependent process. Amino acids leave the skate brain rapidly in response to a sudden decrease in plasma osmolality and/or to a simultaneous drop in extracellular Na+ concentration. However, although amino acids are important for volume regulation in normal brain cells, they do not appear to be likely candidates for the unidentified "idiogenic" osmolytes in mammalian brain cells. The high concentration of taurine in skate myocardium is of special interest because of the special role of this amino acid in myocardial contractility. Thus, unlike beta-alanine and sarcosine, taurine may play a dual role in regulating both cell volume and contractility of myocardial cells. The isolated skate atrium is well suited for in vitro studies of these two processes. PMID:395764

  18. Induction of (+)-abscisic acid 8? hydroxylase by (+)-abscisic acid in cultured maize cells

    Microsoft Academic Search

    Adrian J. Cutler; Timothy M. Squires; Mary K. Loewen; John J. Balsevich

    1997-01-01

    In vivo measurements of the enzymatic hydroxylation of the phytohormone (+)-abscisic acid to hormonally inactive (—)-phaseic acid in corn cell cultures revealed that ( + )-abscisic acid 8' hydroxylase activity was induced by (+)-abscisic acid treatment. This induction was blocked by the protein synthesis inhibitor cyclo- heximide and by the transcription inhibitor cordycepin. Following an induction treatment with abscisic acid,

  19. 21 CFR 172.350 - Fumaric acid and salts of fumaric acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section...Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its...ferrous, magnesium, potassium, and sodium salts may be safely used in food in...

  20. 21 CFR 172.350 - Fumaric acid and salts of fumaric acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section...Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its...ferrous, magnesium, potassium, and sodium salts may be safely used in food in...

  1. 21 CFR 172.350 - Fumaric acid and salts of fumaric acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section...Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its...ferrous, magnesium, potassium, and sodium salts may be safely used in food in...

  2. Method of increasing conversion of a fatty acid to its corresponding dicarboxylic acid

    DOEpatents

    Craft, David L.; Wilson, C. Ron; Eirich, Dudley; Zhang, Yeyan

    2004-09-14

    A nucleic acid sequence including a CYP promoter operably linked to nucleic acid encoding a heterologous protein is provided to increase transcription of the nucleic acid. Expression vectors and host cells containing the nucleic acid sequence are also provided. The methods and compositions described herein are especially useful in the production of polycarboxylic acids by yeast cells.

  3. Effect of formic acid and benzoic acid esters on grass preservation

    E-print Network

    Paris-Sud XI, Université de

    Effect of formic acid and benzoic acid esters on grass preservation A Rauramaa A Tommila J Ltd, Espoo Reseach Centre, PO Box 44, 02271 Espoo, Finland Formic acid is known to improve silage hygienic quality. Formic acid based additive containing propionic and benzoic acids inhibits more

  4. 21 CFR 172.350 - Fumaric acid and salts of fumaric acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2009-04-01 true Fumaric acid and salts of fumaric acid. 172.350 Section 172.350 Food and Drugs...and Nutritional Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid...

  5. 21 CFR 172.350 - Fumaric acid and salts of fumaric acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 2011-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section 172.350 Food and Drugs...and Nutritional Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid...

  6. Influence of dietary essential fatty acid level on fatty acid composition in peripheral nerve and muscle

    E-print Network

    Paris-Sud XI, Université de

    Influence of dietary essential fatty acid level on fatty acid composition in peripheral nerve fed with diets containing different levels of essential unsaturated fatty acids, namely linoleic (18 :2 (n-6)) and linolenic (18 : 2 (n-3)) acid, in the oil. Nerve and muscle fatty acids were analyzed

  7. Erythrocyte stearidonic acid and other n-3 fatty acids and CHD in the Physicians’ Health Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intake of marine-based n-3 fatty acids (EPA, docosapentaenoic acid and DHA) is recommended to prevent CHD. Stearidonic acid (SDA), a plant-based n-3 fatty acid, is a precursor of EPA and may be more readily converted to EPA than a-linolenic acid (ALA). While transgenic soyabeans might supply SDA at ...

  8. Citric Acid Passivation of Stainless Steel

    NASA Technical Reports Server (NTRS)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  9. Enhancers of iron absorption: ascorbic acid and other organic acids.

    PubMed

    Teucher, Birgit; Olivares, Manuel; Cori, Héctor

    2004-11-01

    Ascorbic acid (AA), with its reducing and chelating properties, is the most efficient enhancer of non-heme iron absorption when its stability in the food vehicle is ensured. The number of studies investigating the effect of AA on ferrous sulfate absorption far outweighs that of other iron fortificants. The promotion of iron absorption in the presence of AA is more pronounced in meals containing inhibitors of iron absorption. Meals containing low to medium levels of inhibitors require the addition of AA at a molar ratio of 2:1 (e.g., 20 mg AA: 3 mg iron). To promote absorption in the presence of high levels of inhibitors, AA needs to be added at a molar ratio in excess of 4:1, which may be impractical. The effectiveness of AA in promoting absorption from less soluble compounds, such as ferrous fumarate and elemental iron, requires further investigation. The instability of AA during food processing, storage, and cooking, and the possibility of unwanted sensory changes limits the number of suitable food vehicles for AA, whether used as vitamin fortificant or as an iron enhancer. Suitable vehicles include dry-blended foods, such as complementary, precooked cereal-based infant foods, powdered milk, and other dry beverage products made for reconstitution that are packaged, stored, and prepared in a way that maximizes retention of this vitamin. The consumption of natural sources of Vitamin C (fruits and vegetables) with iron-fortified dry blended foods is also recommended. Encapsulation can mitigate some of the AA losses during processing and storage, but these interventions will also add cost. In addition, the bioavailability of encapsulated iron in the presence/absence of AA will need careful assessment in human clinical trials. The long-term effect of high AA intake on iron status may be less than predicted from single meal studies. The hypothesis that an overall increase of dietary AA intake, or fortification of some foods commonly consumed with the main meal with AA alone, may be as effective as the fortification of the same food vehicle with AA and iron, merits further investigation. This must involve the consideration of practicalities of implementation. To date, programs based on iron and AA fortification of infant formulas and cow's milk provide the strongest evidence for the efficacy of AA fortification. Present results suggest that the effect of organic acids, as measured by in vitro and in vivo methods, is dependent on the source of iron, the type and concentration of organic acid, pH, processing methods, and the food matrix. The iron absorption-enhancing effect of AA is more potent than that of other organic acids due to its ability to reduce ferric to ferrous iron. Based on the limited data available, other organic acids may only be effective at ratios of acid to iron in excess of 100 molar. This would translate into the minimum presence/addition of 1 g citric acid to a meal containing 3 mg iron. Further characterization of the effectiveness of various organic acids in promoting iron absorption is required, in particular with respect to the optimal molar ratio of organic acid to iron, and associated feasibility for food application purposes. The suggested amount of any organic acid required to produce a nutritional benefit will result in unwanted organoleptic changes in most foods, thus limiting its application to a small number of food vehicles (e.g., condiments, beverages). However, fermented foods that already contain high levels of organic acid may be suitable iron fortification vehicles. PMID:15743017

  10. Risk assessment for acid aerosols

    SciTech Connect

    Albert, R.E. (Univ. of Cincinnati Medical Center, OH (USA))

    1989-02-01

    The author provides some insights from carcinogen risk assessment that apply to acid aerosols. The greatest need is to understand mechanisms of action as the basis for characterizing dose response relationships at low levels of exposure. Risk assessment is an orderly assembly of the evidence with some agreed upon guidelines as to how to make judgments about the nature (qualitative assessment) and magnitude (quantitative assessment) of health hazards. Risk assessment provides guidance for regulation, but the impetus for regulation comes from public pressure to remedy perceived health problems. There are some sharp contrasts between carcinogens and acid aerosols in terms of risk assessment and management. The regulatory objective for carcinogens is to diminish the tremendous load of cancer mortality as the second leading cause of death. In the case of acid aerosols, the regulatory objective is less pressing: to eliminate mortality among the moribund from heart and pulmonary disease and the prevention of acute impairments of pulmonary function and acute respiratory infections.

  11. Hydroxamic Acids in Asymmetric Synthesis

    PubMed Central

    Li, Zhi; Yamamoto, Hisashi

    2012-01-01

    Metal-catalyzed stereoselective reactions are a central theme in organic chemistry research. In these reactions, the stereoselection is achieved predominantly by introducing chiral ligands at the metal catalyst’s center. For decades, researchers have sought better chiral ligands for asymmetric catalysis and have made great progress. Nevertheless, to achieve optimal stereoselectivity and to catalyze new reactions, new chiral ligands are needed. Due to their high metal affinity, hydroxamic acids play major roles across a broad spectrum of fields from biochemistry to metal extraction. Dr. K. Barry Sharpless first revealed their potential as chiral ligands for asymmetric synthesis in 1977: He published the chiral vanadium-hydroxamic-acid-catalyzed, enantioselective epoxidation of allylic alcohols before his discovery of Sharpless Asymmetric Epoxidation, which uses titanium-tartrate complex as the chiral reagent. However, researchers have reported few highly enantioselective reactions using metal-hydroxamic acid as catalysts since then. This Account summarizes our research on metal-catalyzed asymmetric epoxidation using hydroxamic acids as chiral ligands. We designed and synthesized a series of new hydroxamic acids, most notably the C2-symmetric bis-hydroxamic acid (BHA) family. V-BHA-catalyzed epoxidation of allylic and homoallylic alcohols achieved higher activity and stereoselectivity than Sharpless Asymmetric Epoxidation in many cases. Changing the metal species led to a series of unprecedented asymmetric epoxidation reactions, such as (i) single olefins and sulfides with Mo-BHA, (ii) homoallylic and bishomoallylic alcohols with Zr- and Hf-BHA, and (iii) N-alkenyl sulfonamides and N-sulfonyl imines with Hf-BHA. These reactions produce uniquely functionalized chiral epoxides with good yields and enantioselectivities. PMID:23157425

  12. Molecular Structure of Oleic acid

    NSDL National Science Digital Library

    2003-05-08

    A mono-unsaturated fatty acid, oleic acid is a component of almost all natural fats. It is obtained from any of various vegetable and animal oils and fats, particularly the seeds of castor, sunflower, safflower, parsley, soybean, flax, perilla, and celery. A colorless or yellow-to-red oily liquid with a lard-like odor, it solidifies to a crystalline mass at four degrees Celsius. When exposed to air it oxidizes and acquires a yellow to brown color and rancid odor; for this reason it should be kept sealed in a container and away from sunlight. It is almost completely insoluble in water but is soluble in alcohol, benzene chloroform, ether, and fixed and volatile oils. Although oleic acid has a low level of toxicity when absorbed orally, it is mildly irritating to the skin and mucous membranes. It also is combustible. Oleic acid is used as a soap base and in the production of food-grade additives, ointments, cosmetics, fragrance products, polishing compounds, surface coatings, and manufacturing driers. It is used for waterproofing textiles and for thickening lubricating oils. It also is used as a solvent in the manufacture of pharmaceuticals. It contributes to the flavor of foods and is found in sweet cider apples. One of the "good" or unsaturated fatty acids, oleic acid has proven helpful to cell and heart function. It has shown anti-inflammatory effects in the body and has been used to treat arthritis, asthma, allergies, and skin conditions. Its inclusion in the diet has improved cases of diabetes, depression, menopausal problems, obesity, memory and learning disabilities, eye problems, and digestive disorders. It is considered to lower the incidence of cancer (as an antioxidant), multiple sclerosis, and lupus as well.

  13. [Uric acid and multiple sclerosis].

    PubMed

    Mattle, H P; Lienert, C; Greeve, I

    2004-09-01

    Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Its etiology is not known, but it is well established that auto-reactive T-cells and monocytes play an important pathogenetic role. Experimental allergic encephalomyelitis (EAE) of mice serves as disease model for MS. In both EAE and MS inflammatory cells produce nitric oxide and its oxidizing congeners such as peroxynitrite. Peroxynitrite and other reactive nitrogen oxide species exert a toxic effect on neurons, axons and glia cells and enhance apoptosis. In addition, they increase the blood-CNS-barrier permeability and can therefore promote invasion of inflammatory cells into the CNS. On the other hand, uric acid, a peroxynitrite scavenger inhibits blood-CNS-barrier permeability changes, CNS inflammation and tissue damage in EAE. Epidemiological studies have shown that MS and gout are almost mutually exclusive diseases. Uric acid levels in MS patients are lower than in controls and in patients with active disease lower than in MS patients in remission. Inosine, a uric acid precursor, can be used to raise uric acid levels in serum and may provide some benefit in MS patients. A small study of ten patients with progressive MS has demonstrated some improved function in three of them and no sign of progression or relapse in the other. However, this study does not justify a recommendation for use of inosine in MS patients yet. At present, uric acid can solely be regarded as a marker of disease activity in MS. In addition, the current knowledge of uric acid and MS supports hypotheses which predict a positive effect of radical scavengers in MS. PMID:15493114

  14. Identification of nine acetylenic fatty acids, 9-hydroxystearic acid and 9,10-epoxystearic acid in the seed oil of Jodina rhombifolia hook et arn. (Santalaceae)

    Microsoft Academic Search

    V. Spitzer; S. A. de L. Bordignon; E. P. Schenkel; F. Marx

    1994-01-01

    In addition to some usual fatty acids, the seed oil ofJodina rhombifolia (Santalaceae) contains nine acetylenic fatty acids [9-octadecynoic acid (stearolic acid) (1.1%),trans-10-heptadecen-8-ynoic acid (pyrulic acid) (20.1%), 7-hydroxy-trans-10-heptadecen-8-ynoic acid (2.3%),trans-10,16-heptadecadien-8-ynoic acid (0.7%), 7-hydroxy-trans-10,16-heptadecadien-8-ynoic acid (0.1%),trans-11-octadecen-9-ynoic acid (ximenynic acid) (20.3%), 8-hydroxy-trans-11-octadecen-9-ynoic acid (12.2%),trans-11,17-octadecadien-9-ynoic acid (1.5%), 8-hydroxy-trans-11,17-octadecadien-9-ynoic acid (1.3%), 9-hydroxystearic acid (<0.1%) and 9,10-epoxystearic acid (0.7%)]. The fatty acids\\u000a have been analyzed

  15. The Nucleic Acid Database (NDB)

    NSDL National Science Digital Library

    Designed by John Westbrook, and housed at Rutgers University, the goal of the NDB is to assemble and distribute structural information about nucleic acids. The database contains the coordinates of nucleic acid-containing crystal structures, including a searchable atlas of structures, Protein Finder, a search-engine for locating protein structures in the PDB database, a macromolecular crystallographic information file, and archived reports about the structures contained in the database. This site provides information of general interest to researchers in the field, and develops and distributes standard geometry information for use in refinement and molecular modeling programs. Users can also subscribe to the NDB electronic newsletter.

  16. Molecular Structure of (+-)-Malic acid

    NSDL National Science Digital Library

    2003-05-08

    Malate, or Malic acid, is found readily in fruits and in the leaves of C4 and CAM plants as storage for carbon dioxide (CO2). In C4 plants, malate is an intermediate during photosynthesis, while in CAM plants it is used to store the CO2 until the stomata are closed at night. It is also key to the production of ATP by the mitochondria. Oxaloacetate is reduced to malate, which is then transported into the mitochondria. Malic acid is frequently used for flavoring of an assortment of products. It is also used as a drug to assist ATP formation, ensuring proper muscle function at even low oxygen levels.

  17. Bipolar lead acid battery development

    NASA Technical Reports Server (NTRS)

    Eskra, Michael; Vidas, Robin; Miles, Ronald; Halpert, Gerald; Attia, Alan; Perrone, David

    1991-01-01

    A modular bipolar battery configuration is under development at Johnson Control, Inc. (JCI) and the Jet Propulsion Laboratory (JPL). The battery design, incorporating proven lead acid electrochemistry, yields a rechargeable, high-power source that is light weight and compact. This configuration offers advantages in power capability, weight, and volume over conventional monopolar batteries and other battery chemistries. The lead acid bipolar battery operates in a sealed, maintenance-free mode allowing for maximum application flexibility. It is ideal for high-voltage and high-power applications.

  18. Synthesis of some alkylarsonic acids

    E-print Network

    McBrearty, Charles Francis

    1967-01-01

    of vrhite crystalline product formed. The mixture vias refluxed for an hour prior to fiitnation. The yield of crude n-dodecylansonic acid was 26. 0 g. Several reer ysta I I i zat ions were carried out from acemone-water mixtures un+ i I a constart r.... For the preparation of arsonic acids with carbon cnains longer than n-C additional precautions were found to be necessary in ihe synthesis of the Grignard reagent. A specially constructed three- I0 necked reaction flask (Fig. I & equioped with reflux condenser...

  19. Acidizing of Sandstone Reservoirs Using HF and Organic Acids 

    E-print Network

    Yang, Fei

    2012-10-19

    , and illite) were examined to react with formic-HF acid mixtures which contain different concentrations of HF. Coreflood experiments on sandstone cores featured by different mineralogy with dimensions of 1.5 in. x 6 in. were also conducted at a flow rate of 5...

  20. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...polyamine condensate, phosphoric acid ester salts. 721.6200 Section 721.6200 ...polyamine condensate, phosphoric acid ester salts. (a) Chemical substances and significant...acid polyamine condensate, phosphate ester salts (PMNs P-90-1984 and...

  1. Microbial conversion of 5-sulfoisophthalic acid into 5-hydroxyisophthalic acid by Ochrobactrum anthropi S9.

    PubMed

    Yamada, Mamoru; Yoshida, Toyokazu; Nagasawa, Toru

    2010-03-01

    5-Hydroxyisophthalic acid-producing microorganisms were isolated from enrichment cultures using 5-sulfoisophthalic acid as a sulfur source. One bacterium, Ochrobactrum anthropi S9, had the highest 5-sulfoisophthalic acid-degrading activity, and stoichiometrically formed 5-hydroxyisophthalic acid, a raw material for polymer synthesis. Under optimum culture conditions, 1.3 mM 5-hydroxyisophthalic acid accumulated in the medium by 60 h. The addition of Na(2)SO(4), L: -methionine or L: -cysteine at 2 mM inhibited the conversion of 5-sulfoisophthalic acid. O. anthropi S9 cells converted 5-sulfoisophthalic acid, benzenesulfonic acid, 3-sulfobenzoic acid, 4-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid and naphthalene-2-sulfonic acid into the corresponding hydroxylated compounds. PMID:19941033

  2. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  3. 40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...

  4. 40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...

  5. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  6. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  7. FORMATION OF ACIDIC TRACE ORGANIC BY-PRODUCTS FROM THE CHLORINATION OF HUMIC ACIDS

    EPA Science Inventory

    A method for concentrating and analyzing acidic trace organics produced by the chlorination of humic acids at concentrations approximating common drinking water levels is described. Data are compared from several humic acid sources. Specific compound analyses of the extracts were...

  8. 46 CFR 151.50-77 - Fluorosilicic acid (30% or less) (hydrofluorosilicic acid).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Fluorosilicic acid (30% or less) (hydrofluorosilicic acid). 151.50-77 Section 151.50-77...Requirements § 151.50-77 Fluorosilicic acid (30% or less) (hydrofluorosilicic...

  9. 40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...

  10. 46 CFR 151.50-77 - Fluorosilicic acid (30% or less) (hydrofluorosilicic acid).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Fluorosilicic acid (30% or less) (hydrofluorosilicic acid). 151.50-77 Section 151.50-77...Requirements § 151.50-77 Fluorosilicic acid (30% or less) (hydrofluorosilicic...

  11. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  12. 40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...

  13. 40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...

  14. Detoxification of ferulic acid by ectomycorrhizal fungi.

    PubMed

    Münzenberger, B; Hammer, E; Wray, V; Schauer, F; Schmidt, J; Strack, D

    2003-04-01

    The ectomycorrhizal fungi Laccaria amethystina and Lactarius deterrimus grown in liquid culture were used to study the fate of added ferulic acid. Laccaria amethystina degraded ferulic acid to the major metabolite vanillic acid. The intermediate vanillin was not detected. Lactarius deterrimus showed a completely different detoxification pattern. Two dimers and one trimer of ferulic acid could be identified as polymerization products of this fungus. A bioassay of the possible biological activities of ferulic acid and vanillic acid on these fungi revealed that vanillic acid was less toxic than ferulic acid for Laccaria amethystina but that both phenolic acids were toxic for Lactarius deterrimus. The results are discussed with respect to ectomycorrhizal fungal growth in the organic layer of forest soils and between living root cells of ectomycorrhizas. PMID:12682834

  15. The utilization of tricarboxylic acid cycle acids and the uptake of succinic acid by Neurospora crassa 

    E-print Network

    Gilliland, Patti Lynn

    1978-01-01

    to 20 140 pH 4. 1 25 C pH 7. 0 g 120 F100 I ~sc E ef 80 Z V lJ ul 40 0 p 40 2 Z 3'C 20 0 0 5 10 15 20 0 5 10 15 20 TIME, minutes Figure 2. Effect of Temperature on Uptake and Accumulation of Succinic Acid. External concentration... of Succinic Acid on Intracellular Concentration of Succinic Acid After 15 Minutes. 32 Id pH 4. 1 pH 1. 0 140 CONTROL 4 CONTROL e 120 V SUFFER 100 4 V V S0 Z V V 0 $ 40 Z 20 / . 7 / js I 4 e SUFFER I. / I 0 5 10 'IS 20 0 S 10 15 20...

  16. Bioconversion of fumaric acid to succinic acid by recombinant E. coli

    Microsoft Academic Search

    Xiaohai Wang; C. S. Gong; George T. Tsao

    1998-01-01

    Succinic acid was produced efficiently from fumaric acid by a recombinantE. coli strain DH5?t\\/pGC1002 containing multicopy fumarate reductase genes. The effects of initial fumaric acid and glucose concentration\\u000a on the production of succinic acid were investigated. Succinic acid reached 41 to over 60 g\\/L in 48.5 h starting with 50 to\\u000a 64 g\\/L fumaric acid. Significant substrate inhibition was observed

  17. Role of oleic acid in the metabolism of essential fatty acids

    Microsoft Academic Search

    G. A. Dhopeshwarkar; James F. Mead

    1961-01-01

    Groups of young male guinea pigs were fed diets containing corn oil, coconut oil, coconut oil plus elaidic acid, and coconut\\u000a oil plus oleic acid. The oleic acid-fed group showed signs of essential fatty acid deficiency after four weeks and severe\\u000a signs after eight weeks. The elaidic acid-fed group did not show these symptoms. It is proposed that oleic acid

  18. Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

    SciTech Connect

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1986-02-01

    Human keratinocytes in culture were labelled with /sup 14/C-dihomo-gamma-linolenic acid, /sup 14/C-arachidonic acid or /sup 14/C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes.

  19. Fatty Acid Based Biodegradable Polymer

    Microsoft Academic Search

    Jay Prakash Jain; Marina Sokolsky; Neeraj Kumar; A. J. Domb

    2008-01-01

    Synthetic polymers have become an indispensable part of the daily?life of human beings and the biodegradable class of polymers hold immense value in therapeutics. Fatty acid incorporation in biodegradable polymers renders flexibility, low melting point, hydrophobicity, and pliability properties. At the same time, degradation into naturally occurring compounds makes them environmentally friendly besides their utility in various applications like drug

  20. Solution properties of polygalacturonic acid

    PubMed Central

    Stoddart, R. W.; Spires, I. P. C.; Tipton, K. F.

    1969-01-01

    1. The specimen of polygalacturonic acid used in these studies was shown to contain very little neutral sugar, methyl ester groups or ash, and only residues of galacturonic acid. Its electrophoretic homogeneity was examined in pyridine–acetic acid buffer at pH6·5 and in borate buffer at pH9·2. The distribution of effective particle weights was shown to be fairly narrow. 2. The pH-titration curve of the polymer gave a pK value of 3·7. 3. The interaction of the polymer with Ruthenium Red was studied and titration curves were obtained for the spectral shifts associated with the formation of a complex. 4. Optical-rotatory-dispersion studies showed that the Drude constant, ?c, was dependent on pH. 5. Polygalacturonic acid was shown to display non-Newtonian properties in solution and to have an anomalously high relative specific viscosity at low concentrations. 6. Studies were made of the pH-dependence of the sedimentation coefficient of the polymer. 7. These results are discussed in terms of the structure of the molecule and their relevance to the properties of pectic substances. PMID:5343801